KR102654431B1 - Composition for holographic recording medium and holographic recording medium - Google Patents

Abstract

Component (e): A composition for a hologram recording medium containing an isocyanate group or a compound having an isocyanate-reactive functional group and a nitroxyl radical group, wherein component (e) includes the following component (e-1). Composition for media. Component (e-1): A compound having a heterobicyclo ring structure or heterotricyclo ring structure in which the carbon atom of the bicyclo ring structure or tricyclo ring structure is substituted with a nitroxyl radical group.

Description

Composition for holographic recording medium and holographic recording medium

The present invention relates to a composition for a hologram recording medium, a cured product for a hologram recording medium obtained by curing the composition for a hologram recording medium, and a hologram recording medium using the composition for a hologram recording medium.

To further increase the capacity and density of optical recording media, holographic optical recording media that records information as a hologram by changing the refractive index of the recording layer according to the light intensity distribution due to light interference are being developed.

Recently, studies have been conducted to apply hologram recording media, which have been developed for memory applications, to optical element applications of AR glass light guide plates (for example, patent document 1).

For the following reasons, it is preferable that the performance index M/# of the hologram recording medium is higher.

In memory applications, the higher the M/#, the better the recording capacity.

When using an AR glass light guide plate as an optical element, a higher M/# can expand the viewing angle, reduce color unevenness, and improve luminance.

Patent Document 2 discloses, as a technique for improving M/#, a method of adding a compound (for example, TEMPOL) having both a functional group that chemically bonds to the matrix and a stable nitroxyl radical group to the composition.

It is known that ABNO and AZADO used in the present invention have high catalytic activity in the oxidation reaction of alcohol.

US Patent Application Publication No. 2017/0059759 Specification US Patent No. 8658332 Specification Japanese Patent Publication No. 2011-153076 International Publication No. 2013/125688

Polymer Journal 2007, Volume 64, Issue 6, 329-342p (Polymer Society, a public interest corporation)

Through examination by the present inventor, it was found that the medium to which TEMPOL was added had a lower M/# under accelerated test conditions, that is, had poor thermal stability. This is believed to be because the dormant species composed of nitroxyl radicals and polymer radicals in the medium were ten-cleaved, and the polymer diffused into the matrix.

According to Non-Patent Document 1, the dissociation energy of the NO-C bond of the doment species derived from TEMPO is experimentally estimated to be 116 to 146 kJ/mol. This means that thermal cleavage proceeds under heating conditions of 70°C or higher.

If M/# is lowered, it is undesirable for AR glass light guide plates to be used as optical elements, as it leads to a reduction in viewing angle, an increase in color unevenness, and a decrease in luminance.

ABNO and AZADO disclosed in Patent Documents 3 and 4 are known to have high activity as catalysts for the oxidation reaction of alcohol. However, there have been no reports of using these compounds for hologram recording media purposes.

The present invention is a composition for holographic recording media containing an additive having a nitroxyl radical group for improving M/#, which can achieve a higher M/# improvement effect than TEMPOL and has excellent M/# thermal stability. The task is to provide a hologram recording medium.

The present inventor has found that in hologram recording media to which ABNO and AZADO, which have functional groups that chemically bond to the matrix, are added, M/# is further improved compared to when TEMPOL is added, and the decline in M/# under accelerated test conditions is suppressed. found out

Although the details of these effects are not clear, they are estimated as follows.

ABNO and AZADO have smaller steric hindrance around the nitroxyl group compared to TEMPOL, and the M/# is improved because the radical capture efficiency is higher than that of TEMPOL in the matrix of the hologram recording medium.

Since there is no need for radicals to be spatially twisted and combined as in the case of TEMPOL, the energy of the dormant species is low and the activation energy of ten cleavage is large. Because of this, it is difficult to dehisce.

The main point of the present invention is as follows.

[1] Component (e): A composition for hologram recording media containing an isocyanate group or a compound having an isocyanate-reactive functional group and a nitroxyl radical group, wherein component (e) includes the following component (e-1). A composition for a holographic recording medium.

Component (e-1): A compound having a heterobicyclo ring structure or heterotricyclo ring structure in which the carbon atom of the bicyclo ring structure or tricyclo ring structure is substituted with a nitroxyl radical group.

[2] Component (e): A composition for hologram recording media containing an isocyanate group or a compound having an isocyanate-reactive functional group and a nitroxyl radical group, wherein component (e) includes the following component (e-2). A composition for a holographic recording medium.

Component (e-2): Compound represented by the following formula (I)

[Formula 1]

In formula (I), C ₁ and C ₂ represent carbon atoms. In formula ( _{I )} , ^{two R When R ​} _​ ^​ _​ ^​ _​

In formula (I), and R ^A in the linking group is hydrogen atom, halogen atom, C1-12 alkyl group, hydroxy group, hydroxy(C1-12 alkyl) group, amino group, amino(C1-12 alkyl) It represents a substituent selected from group, isocyanate group, and isocyanate (C1-12 alkyl) group. In addition, R ^A in formula (I) and in the above linking group is bonded to one or two carbon atoms of the bicyclo ring structure or tricyclo ring structure, respectively, and when the substituent is two or more, The substituents may be the same or different. A plurality of R ^A in formula (I) and the above linking group may be the same or different.

However, at least one of R ^A in formula (I) and the linking group is selected from a hydroxy group, a hydroxy (C1-12 alkyl) group, an amino group, an amino (C1-12 alkyl) group, and an isocyanate group. represents one or more substituents.

[3] The hologram recording medium according to [1] or [2], wherein the composition for a hologram recording medium further comprises a matrix resin, component (c): a polymerizable monomer, and component (d): a photopolymerization initiator. Composition for.

[4] The composition for a hologram recording medium according to [3], wherein the matrix resin is obtained by reaction of component (a): a compound having an isocyanate group and component (b): a compound having an isocyanate-reactive functional group.

[5] A composition for a hologram recording medium containing the following components (a) to (e), wherein the component (e) contains the following component (e-1).

Component (a): Compound having an isocyanate group

Component (b): Compound having an isocyanate reactive functional group

Component (c): Polymerizable monomer

Component (d): Photopolymerization initiator

Component (e): A compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group.

Component (e-1): A compound having a heterobicyclo ring structure or heterotricyclo ring structure in which the carbon atom of the bicyclo ring structure or tricyclo ring structure is substituted with a nitroxyl radical group.

[6] A composition for a hologram recording medium containing the following components (a) to (e), wherein the component (e) contains the following component (e-2).

Component (a): Compound having an isocyanate group

Component (b): Compound having an isocyanate reactive functional group

Component (c): Polymerizable monomer

Component (d): Photopolymerization initiator

Component (e): A compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group.

Component (e-2): Compound represented by the following formula (I)

[Formula 2]

In formula (I), C ₁ and C ₂ represent carbon atoms. In formula ( _{I )} , ^{two R When R ​} _​ ^​ _​ ^​ _​

In formula (I), and R ^A in the linking group is hydrogen atom, halogen atom, C1-12 alkyl group, hydroxy group, hydroxy(C1-12 alkyl) group, amino group, amino(C1-12 alkyl) It represents a substituent selected from group, isocyanate group, and isocyanate (C1-12 alkyl) group. In addition, R ^A in formula (I) and in the above linking group is bonded to one or two carbon atoms of the bicyclo ring structure or tricyclo ring structure, respectively, and when the substituent is two or more, The substituents may be the same or different. A plurality of R ^A in formula (I) and the above linking group may be the same or different.

However, at least one of R ^A in formula (I) and the linking group is selected from a hydroxy group, a hydroxy (C1-12 alkyl) group, an amino group, an amino (C1-12 alkyl) group, and an isocyanate group. represents one or more substituents.

[7] The composition for a hologram recording medium according to [2] or [6], wherein the compound represented by the formula (I) is a compound represented by any of the following formulas (Ia) to (Ic).

[Formula 3]

R ^A in formulas (Ia) to (Ic) has the same meaning as in formula (I).

[8] A composition for a hologram recording medium containing the following components (a) to (e), wherein the component (e) contains the following component (e-3).

Component (a): Compound having an isocyanate group

Component (b): Compound having an isocyanate reactive functional group

Component (c): Polymerizable monomer

Component (d): Photopolymerization initiator

Component (e): A compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group.

Component (e-3): A compound whose nitroxyl radical group is not subjected to steric hindrance, and is selected from the following (e-3-1) to (e-3-3)

(e-3-1): A compound in which the number of alkyl groups covalently bonded to each of the two atoms covalently bonded to the nitrogen atom of the nitroxyl radical group is 0 or 1.

(e-3-2): A compound in which among the two carbon atoms covalently bonded to the nitrogen atom of the nitroxyl radical group, at least one carbon atom is covalently bonded to one or more hydrogen atoms or halogen atoms.

(e-3-3): A compound in which both of the two carbon atoms covalently bonded to the nitrogen atom of the nitroxyl radical group are covalently bonded to one or more hydrogen atoms or halogen atoms.

[9] A composition for a hologram recording medium containing the following components (a) to (e), wherein the component (e) contains the following component (e-4).

Component (a): Compound having an isocyanate group

Component (b): Compound having an isocyanate reactive functional group

Component (c): Polymerizable monomer

Component (d): Photopolymerization initiator

Component (e): A compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group.

Component (e-4): A compound in which an isocyanate group or an isocyanate reactive group is substituted in the compound parent having a nitroxy radical group, and the redox potential of the compound parent having a nitroxy radical group is 280 mV or less.

[10] Among [4] to [9], wherein the ratio of the total weight of propylene glycol units and tetramethylene glycol units contained in component (b) to the total weight of component (a) and component (b) is 30% or less. The composition for a hologram recording medium according to any one of the above.

[11] The composition for a hologram recording medium according to [10], wherein the weight ratio of the caprolactone unit contained in component (b) to the total weight of component (a) and component (b) is 20% or more.

[12] The composition for a hologram recording medium according to any one of [4] to [11], further comprising the following component (f).

Component (f): Curing catalyst

[13] The composition for a hologram recording medium according to any one of [3] to [12], wherein the molar ratio (component (e)/component (d)) of component (e) and component (d) in the composition is 0.1 or more and 10 or less. .

[14] [3] to [13], wherein the content of component (c) in the composition is 0.1% by weight or more and 80% by weight or less, and the content of component (d) is 0.1% by weight or more and 20% by weight or less relative to component (c). ] The composition for a hologram recording medium according to any one of the above.

[15] The total content of component (a) and component (b) in the composition is 0.1% by weight or more and 99.9% by weight or less, and the number of isocyanate reactive functional groups contained in component (b) relative to the number of isocyanate groups contained in component (a) The composition for a hologram recording medium according to any one of [4] to [14], wherein the ratio is 0.1 or more and 10.0 or less.

[16] A cured product for a hologram recording medium obtained by curing the composition for a hologram recording medium according to any one of [1] to [15].

[17] A laminate for a hologram recording medium, which has the cured material for a hologram recording medium according to [16] as a recording layer, and has a support on the upper and/or lower side of the recording layer.

[18] A hologram recording medium obtained by subjecting the cured material for a hologram recording medium according to [16] or the laminate for a hologram recording medium according to [17] to interference exposure.

[19] The hologram recording medium described in [18], which is an AR glass light guide plate.

According to the present invention, M/# is further improved compared to conventional hologram recording media, the thermal stability of M/# is excellent, and deterioration of M/# over time in a high temperature environment is suppressed. Media can be provided.

For this reason, especially in AR glass light guide plate applications, the viewing angle can be expanded, color unevenness can be reduced, luminance can be improved, and thermal stability can be improved.

Additionally, even in memory applications, recording capacity can be improved and signal thermal stability can be improved.

1 is a configuration diagram showing an outline of a device used for hologram recording in an example.
Figure 2 is a graph showing the relationship between M/# and the addition amount of additives (additive/component (d) (molar ratio)) in Examples 1 to 10 and Comparative Examples 2 to 9.
Figure 3 is a diagram showing the evaluation results of the archival life of the hologram recording medium of Comparative Example 4. Fig.3a is a graph showing the change in M/# over time. Fig.3b is a graph showing the diffraction efficiency of sample No. 1 at the start of the test. Fig.3c is a graph showing the diffraction efficiency of sample No. 1 after 800 hours of acceleration test.
Fig. 4 is a diagram showing the evaluation results of the archival life of the hologram recording medium of Comparative Example 7. Fig.4a is a graph showing the change in M/# over time. Fig.4b is a graph showing the diffraction efficiency of sample No. 1 at the start of the test. Fig.4c is a graph showing the diffraction efficiency of sample No. 1 after an accelerated test for 870 hours.
Fig. 5 is a diagram showing the evaluation results of the archival life of the hologram recording medium of Example 3. Fig.5a is a graph showing the change in M/# over time. Fig.5b is a graph showing the diffraction efficiency of sample No. 1 at the start of the test. Fig.5c is a graph showing the diffraction efficiency of sample No. 1 after 800 hours of acceleration test.
Fig. 6 is a diagram showing the evaluation results of the archival life of the hologram recording medium of Example 7. Fig.6a is a graph showing the change in M/# over time. Fig.6b is a graph showing the diffraction efficiency of sample No. 1 at the start of the test. Fig.6c is a graph showing the diffraction efficiency of sample No. 1 after an 857-hour acceleration test.
Fig. 7 is a diagram showing the evaluation results of the archival life of the hologram recording medium of Example 10. Fig.7a is a graph showing the change in M/# over time. Fig.7b is a graph showing the diffraction efficiency of sample No. 1 at the start of the test. Fig.7c is a graph showing the diffraction efficiency of sample No. 1 after 800 hours of acceleration test.

EMBODIMENT OF THE INVENTION Embodiments of this invention are described in detail below. The matters and methods illustrated below are examples (representative examples) of embodiments of the present invention, and the present invention is not specified by these contents unless it deviates from the gist.

[Composition for holographic recording medium]

A composition for a hologram recording medium according to one aspect of the present invention is a composition for a hologram recording medium containing component (e): a compound having an isocyanate group or an isocyanate reactive functional group and a nitroxyl radical group, wherein component (e) contains the following components: It is characterized by including (e-1).

Component (e-1): A compound having a heterobicyclo ring structure or heterotricyclo ring structure in which the carbon atom of the bicyclo ring structure or tricyclo ring structure is substituted with a nitroxyl radical group.

A composition for a hologram recording medium according to one aspect of the present invention is a composition for a hologram recording medium containing component (e): a compound having an isocyanate group or an isocyanate reactive functional group and a nitroxyl radical group, wherein component (e) contains the following components: It is characterized by including (e-2).

Component (e-2): Compound represented by the following formula (I)

[Formula 4]

In formula (I), C ₁ and C ₂ represent carbon atoms. In formula ( _{I )} , ^{two R When R ​} _​ ^​ _​ ^​ _​

In formula (I), and R ^A in the linking group is hydrogen atom, halogen atom, C1-12 alkyl group, hydroxy group, hydroxy(C1-12 alkyl) group, amino group, amino(C1-12 alkyl) It represents a substituent selected from group, isocyanate group, and isocyanate (C1-12 alkyl) group. In addition, R ^A in formula (I) and in the above linking group is bonded to one or two carbon atoms of the bicyclo ring structure or tricyclo ring structure, respectively, and when the substituent is two or more, The substituents may be the same or different. A plurality of R ^A in formula (I) and the above linking group may be the same or different.

However, at least one of R ^A in formula (I) and the linking group is selected from a hydroxy group, a hydroxy (C1-12 alkyl) group, an amino group, an amino (C1-12 alkyl) group, and an isocyanate group. represents one or more substituents.

The composition for a hologram recording medium may further include a matrix resin, component (c): a polymerizable monomer, and component (d): a photopolymerization initiator.

In this case, the matrix resin may be obtained by reaction of component (a): a compound having an isocyanate group and component (b): a compound having an isocyanate-reactive functional group.

A composition for a hologram recording medium according to one aspect of the present invention is a composition for a hologram recording medium containing the following components (a) to (e), wherein the component (e) includes the following component (e-1). Do it as

Component (a): Compound having an isocyanate group

Component (b): Compound having an isocyanate reactive functional group

Component (c): Polymerizable monomer

Component (d): Photopolymerization initiator

Component (e): A compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group.

Component (e-1): A compound having a heterobicyclo ring structure or heterotricyclo ring structure in which the carbon atom of the bicyclo ring structure or tricyclo ring structure is substituted with a nitroxyl radical group.

A composition for a hologram recording medium according to one aspect of the present invention is a composition for a hologram recording medium containing the following components (a) to (e), wherein the component (e) includes the following component (e-2). Do it as

Component (a): Compound having an isocyanate group

Component (b): Compound having an isocyanate reactive functional group

Component (c): Polymerizable monomer

Component (d): Photopolymerization initiator

Component (e): A compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group.

Component (e-2): Compound represented by the following formula (I)

[Formula 5]

In formula (I), C ₁ and C ₂ represent carbon atoms. In formula ( _{I )} , ^{two R When R ​} _​ ^​ _​ ^​ _​

In formula (I), and R ^A in the linking group is hydrogen atom, halogen atom, C1-12 alkyl group, hydroxy group, hydroxy(C1-12 alkyl) group, amino group, amino(C1-12 alkyl) It represents a substituent selected from group, isocyanate group, and isocyanate (C1-12 alkyl) group. In addition, R ^A in formula (I) and in the above linking group is bonded to one or two carbon atoms of the bicyclo ring structure or tricyclo ring structure, respectively, and when the substituent is two or more, The substituents may be the same or different. A plurality of R ^A in formula (I) and the above linking group may be the same or different.

However, at least one of R ^A in formula (I) and the linking group is selected from a hydroxy group, a hydroxy (C1-12 alkyl) group, an amino group, an amino (C1-12 alkyl) group, and an isocyanate group. represents one or more substituents.

A composition for a hologram recording medium according to one aspect of the present invention is a composition for a hologram recording medium containing the following components (a) to (e), wherein the component (e) includes the following component (e-3). Do it as

Component (a): Compound having an isocyanate group

Component (b): Compound having an isocyanate reactive functional group

Component (c): Polymerizable monomer

Component (d): Photopolymerization initiator

Component (e): A compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group.

Component (e-3): A compound whose nitroxyl radical group is not subjected to steric hindrance, and is selected from the following (e-3-1) to (e-3-3)

(e-3-1): A compound in which the number of alkyl groups covalently bonded to each of the two atoms covalently bonded to the nitrogen atom of the nitroxyl radical group is 0 or 1.

(e-3-2): A compound in which among the two carbon atoms covalently bonded to the nitrogen atom of the nitroxyl radical group, at least one carbon atom is covalently bonded to one or more hydrogen atoms or halogen atoms.

(e-3-3): A compound in which both of the two carbon atoms covalently bonded to the nitrogen atom of the nitroxyl radical group are covalently bonded to one or more hydrogen atoms or halogen atoms.

A composition for a hologram recording medium according to one aspect of the present invention is a composition for a hologram recording medium containing the following components (a) to (e), wherein the component (e) includes the following component (e-4). Do it as

Component (a): Compound having an isocyanate group

Component (b): Compound having an isocyanate reactive functional group

Component (c): Polymerizable monomer

Component (d): Photopolymerization initiator

Component (e): A compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group.

Component (e-4): A compound in which an isocyanate group or an isocyanate reactive group is substituted in the compound parent having a nitroxy radical group, and the redox potential of the compound parent having a nitroxy radical group is 280 mV or less.

＜Component (a)＞

The compound having an isocyanate group of component (a) reacts with a compound having an isocyanate-reactive functional group (component (b)), preferably in the presence of a curing catalyst (component (f)) described later, to form a component that constitutes the resin matrix. am.

The proportion of isocyanate groups in the molecule of the compound having an isocyanate group is preferably 50% by weight or less, more preferably 47% by weight or less, and still more preferably 45% by weight or less. This lower limit is usually 0.1% by weight, and is preferably 1% by weight. When the ratio of isocyanate groups is less than the above upper limit, cloudiness is less likely to occur when used as a hologram recording medium, and optical uniformity is achieved. When the ratio of isocyanate groups is greater than the above lower limit, the hardness and glass transition temperature of the resin matrix increase, and loss of recording can be prevented.

The ratio of isocyanate groups in the present invention represents the ratio of isocyanate groups in the entire compound having an isocyanate group to be used. The ratio of the isocyanate group in the compound having the isocyanate group is obtained from the following formula. The molecular weight of the isocyanate group is 42.

(42 × number of isocyanate groups/molecular weight of the compound having an isocyanate group) × 100

There is no particular limitation on the type of compound having an isocyanate group, and for example, it may have an aromatic, aromatic aliphatic, aliphatic, or alicyclic skeleton.

The compound having an isocyanate group may have one isocyanate group in the molecule, or may have two or more isocyanate groups. The compound having an isocyanate group preferably has two or more isocyanate groups in the molecule. This includes a compound having 2 or more isocyanate groups in the molecule (component (a)), a compound having 3 or more isocyanate reactive functional groups in the molecule (component (b)), or a compound having 3 or more isocyanate groups in the molecule (component (a) )) and a compound having two or more isocyanate-reactive functional groups in the molecule (component (b)). This is because a recording layer with excellent record retention properties can be obtained.

Compounds having an isocyanate group include, for example, isocyanic acid, butyl isocyanate, octyl isocyanate, butyl diisocyanate, hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), 1,8- Diisocyanato-4-(isocyanatomethyl)octane, 2,2,4- and/or 2,4,4-trimethylhexamethylene diisocyanate, isomer bis(4,4'-isocyanatocyclohexyl)methane and mixtures thereof having any desired isomer content, isocyanatomethyl-1,8-octanediisocyanate, 1,4-cyclohexylenediisocyanate, isomeric cyclohexanedimethylenediisocyanate, 1,4-phenylenediisocyanate, 2,4- and/or 2,6-toluene diisocyanate, 1,5-naphthylene diisocyanate, 2,4'- or 4,4'-diphenylmethane diisocyanate and/or triphenylmethane 4,4' , 4''-triisocyanate, etc. can be mentioned.

Compounds having an isocyanate group include urethane, urea, carbodiimide, acrylurea, isocyanurate, allophanate, biuret, oxadiazinetrione, urethione, and/or isocyanate derivatives having an iminooxadiazinedione structure. It is also possible to use

Any one of these may be used individually, and two or more types may be used together in any combination and ratio.

Among the above, aliphatic or alicyclic compounds having an isocyanate group are preferred because they are difficult to color.

＜Component (b)＞

The compound having an isocyanate-reactive functional group of component (b) is a compound having active hydrogen (isocyanate-reactive functional group) involved in a chain extension reaction with the compound having an isocyanate group of component (a).

Examples of the isocyanate-reactive functional group include a hydroxyl group, an amino group, and a mercapto group.

The compound having an isocyanate-reactive functional group may have one isocyanate-reactive functional group in the molecule, or may have two or more isocyanate-reactive functional groups. The compound having an isocyanate-reactive functional group preferably has two or more isocyanate-reactive functional groups in the molecule. When it has two or more isocyanate-reactive functional groups, one type of isocyanate-reactive functional group contained in one molecule may be sufficient, and more than one type may be sufficient as it.

The number average molecular weight of the compound having an isocyanate-reactive functional group is usually 50 or more, preferably 100 or more, more preferably 150 or more, usually 50,000 or less, preferably 10,000 or less, and more preferably 5,000 or less. When the number average molecular weight of the compound having an isocyanate-reactive functional group is more than the above lower limit, the crosslinking density decreases, and a decrease in recording speed can be prevented. When the number average molecular weight of the compound having an isocyanate-reactive functional group is below the above upper limit, compatibility with other components improves or the crosslinking density increases, thereby preventing loss of recorded content.

The number average molecular weight of component (b) is a value measured by gel permeation chromatography (GPC).

(Compound with hydroxyl group)

A compound having a hydroxyl group as an isocyanate-reactive functional group may have one or more hydroxyl groups in one molecule, but preferably has two or more hydroxyl groups. Examples include glycols such as ethylene glycol, triethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol (PPG), and neopentyl glycol; Diols such as butanediol, pentanediol, hexanediol, heptanediol, tetramethylene glycol (TMG), and polytetramethylene glycol (PTMG); Compounds obtained by modifying bisphenols or polyfunctional alcohols thereof with polyethyleneoxy chains or polypropyleneoxy chains; Compounds obtained by modifying these polyfunctional alcohols such as triols such as glycerin, trimethylolpropane, butanetriol, pentanetriol, hexanetriol, and decantriol with polyethyleneoxy chains or polypropyleneoxy chains; Multifunctional polyoxybutylene; Multifunctional polycaprolactone; Multifunctional polyester; Multifunctional polycarbonate; and multifunctional polypropylene glycol. Any one of these may be used individually, and two or more types may be used together in any combination and ratio.

The number average molecular weight of the compound having a hydroxyl group is usually 50 or more, preferably 100 or more, more preferably 150 or more, and usually 50,000 or less, preferably 10,000 or less, and more preferably 5,000 or less. When the number average molecular weight of the compound having a hydroxyl group is more than the above lower limit, the crosslinking density is lowered, and a decrease in recording speed can be prevented. When the number average molecular weight of the compound having a hydroxyl group is below the above upper limit, compatibility with other components improves or the crosslinking density increases, so loss of recorded content can be prevented.

(Compound with amino group)

The compound having an amino group as the isocyanate-reactive functional group may have one or more amino groups in one molecule, but it is preferable that it has two or more amino groups. Examples include aliphatic amines such as ethylenediamine, diethylenetriamine, triethylenetetramine, and hexamethylenediamine; Alicyclic amines such as isophorone diamine, menthanediamine, and 4,4'-diaminodicyclohexylmethane; Aromatic amines such as m-xylylenediamine, diaminodiphenylmethane, and m-phenylenediamine; etc. can be mentioned. Any one of these may be used individually, and two or more types may be used together in any combination and ratio.

The number average molecular weight of the compound having an amino group is usually 50 or more, preferably 100 or more, more preferably 150 or more, and is usually 50,000 or less, preferably 10,000 or less, and more preferably 5,000 or less. When the number average molecular weight of the compound having an amino group is more than the above lower limit, the crosslinking density is lowered, and a decrease in recording speed can be prevented. When the number average molecular weight of the compound having an amino group is below the above upper limit, compatibility with other components improves or the crosslinking density increases, so loss of recorded content can be prevented.

(Compound having a mercapto group)

The compound having a mercapto group as an isocyanate-reactive functional group may have one or more mercapto groups in one molecule, but it is preferable to have two or more mercapto groups. Examples include 1,3-butanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 1,2-benzenedithiol, 1,3-benzeneditiol, 1,4-benzeneditiol. All, 1,10-decanedithiol, 1,2-ethanedithiol, 1,6-hexanedithiol, 1,9-nonanedithiol, pentaerythritol tetrakis(3-mercaptopropionate), penta Erythritol tetrakis (2-mercaptoacetate), pentaerythritol tetrakis (3-mercaptobutyrate), trimethylolpropane tris (3-mercaptopropionate), dipentaerythritol hexakis (3-mercapto propionate), 1,4-bis(3-mercaptobutyryloxy)butane, etc. Any one of these may be used individually, and two or more types may be used together in any combination and ratio.

The number average molecular weight of the compound having a mercapto group is usually 50 or more, preferably 100 or more, more preferably 150 or more, and usually 50,000 or less, preferably 10,000 or less, and more preferably 5,000 or less. When the number average molecular weight of the compound having a mercapto group is more than the above lower limit, the crosslinking density decreases, and a decrease in recording speed can be prevented. When the number average molecular weight of the compound having a mercapto group is below the above upper limit, compatibility with other components improves or the crosslinking density increases, so loss of recorded content can be prevented.

(Preferred component (b) for the present invention)

The present inventor has found that when a compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group is used as component (e), the propylene glycol (PG) unit and tetramethylene glycol (TMG) unit contained in component (b) are used. It was found that the hologram recording medium is colored. From the viewpoint of suppressing coloring of the hologram recording medium, the ratio of the total weight of the PG unit and the TMG unit contained in component (b) (hereinafter described as “(PG + TMG) / ((a) + (b))” In some cases, the smaller the , the more the coloring of the hologram recording medium can be reduced. From the viewpoint of suppressing coloring of the hologram recording medium, (PG + TMG)/((a) + (b)) of the composition for hologram recording medium of the present invention is 30% or less, especially 27% or less, especially 25% or less. is preferred, and 0% (not including PG units and TMG units) is most preferred.

In order to keep (PG + TMG)/((a) + (b)) below the above upper limit, a PG unit or TMG unit such as polypropylene glycol (PPG) or polytetramethylene glycol (PTMG) is used as component (b). It is not desirable to use a compound having . When using a compound having a PG unit or a TMG unit, it is used so that (PG + TMG)/((a) + (b)) in the composition is below the above upper limit.

As component (b), it is preferable to use polycaprolactone from the viewpoint of suppressing coloring. By using polycaprolactone as component (b), the caprolactone (CL) unit contained in component (b) relative to the total weight of component (a) and component (b) in the composition for hologram recording media of the present invention. The weight ratio (hereinafter sometimes written as "(CL)/((a) + (b))") is designed to be 20% or more, especially 25% or more, especially 30 to 70%. desirable. Here, the CL unit refers to a caprolactone-derived unit (ring-opened chain unit) contained in polycaprolactone.

Polycaprolactones used as component (b) include, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, and hexamethylene. Polyvalents such as glycol, methylpentanediol, 2,4-diethylpentanediol, neopentylglycol, 2-ethyl-1,3-hexanediol, trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, etc. Examples include polycaprolactone polyols (polycaprolactone diol, polycaprolactone triol, etc.) obtained by ring-opening polymerization of ε-caprolactone in the presence of diols such as alcohol, polypropylene glycol, and polytetramethylene glycol (PTMG). there is. Any one of these may be used individually, and two or more types may be used together in any combination and ratio.

In the present invention, it is preferable to include the above-mentioned polycaprolactone polyol as component (b). For example, it is preferable to use only polycaprolactone polyol, or to use polycaprolactone polyol in combination with the other component (b). In particular, it is preferable to use only polycaprolactone polyol as component (b) to make (CL)/((a) + (b)) in the composition more than the above lower limit.

If (PG + TMG)/((a) + (b)) in the composition is below the above upper limit, as component (b), a polyol having a PG unit or TMG unit such as polypropylene glycol is modified with ε-caprolactone or the like. By doing so, it is also possible to use one incorporating a CL unit.

＜Component (c)＞

The polymerizable monomer of component (c) is a compound that can be polymerized by the photopolymerization initiator of component (d) described later. Component (c) is a monomer compound that is polymerized during recording and/or post-exposure. The type of polymerizable monomer used in the composition for a hologram recording medium of the present invention is not particularly limited, and can be appropriately selected from known compounds. Examples of polymerizable monomers include cationically polymerizable monomers, anionic polymerizable monomers, and radically polymerizable monomers. Any of these may be used, and two or more types may be used together.

For the reason that it is difficult for a compound having an isocyanate group and a compound having an isocyanate-reactive functional group to inhibit the reaction forming the matrix, it is preferable to use a radically polymerizable monomer.

(Cationic polymerizable monomer)

Examples of cationically polymerizable monomers include epoxy compounds, oxetane compounds, oxolane compounds, cyclic acetal compounds, cyclic lactone compounds, thiirane compounds, thiethane compounds, vinyl ether compounds, spiroorthoester compounds, and ethylenically unsaturated compounds. Examples include bonding compounds, cyclic ether compounds, cyclic thioether compounds, and vinyl compounds. As for the said cationically polymerizable monomer, any one type may be used individually, and 2 or more types may be used together in arbitrary combinations and ratios.

(Anionic polymerizable monomer)

Examples of anionic polymerizable monomers include hydrocarbon monomers and polar monomers.

Examples of hydrocarbon monomers include styrene, α-methylstyrene, butadiene, isoprene, vinylpyridine, vinylanthracene, and derivatives thereof.

Examples of polar monomers include methacrylic acid esters, acrylic acid esters, vinyl ketones, isopropenyl ketones, and other polar monomers.

The anionically polymerizable monomers in the examples above may be used individually, or two or more types may be used together in any combination and ratio.

(radical polymerizable monomer)

Examples of radically polymerizable monomers include compounds having a (meth)acryloyl group, (meth)acrylamides, vinyl esters, vinyl compounds, styrenes, and spiro ring-containing compounds. The radically polymerizable monomers of the above examples may be used individually, or two or more types may be used together in any combination and ratio.

In this specification, the generic name for methacryl and acrylic is described as (meth)acrylic.

Among the above, compounds having a (meth)acryloyl group are more preferable from the viewpoint of steric hindrance during radical polymerization.

(Molecular weight of polymerizable monomer)

The polymerizable monomer used in the composition for a hologram recording medium of the present invention usually has a molecular weight of 80 or more, preferably 150 or more, more preferably 300 or more, and usually 3000 or less, preferably 2500 or less, more preferably It is less than 2000. When the molecular weight is more than the above lower limit, the shrinkage rate caused by polymerization of light irradiation when recording hologram information can be reduced. When the molecular weight is below the above upper limit, the mobility of the polymerizable monomer in the recording layer using the composition for a hologram recording medium is high, diffusion easily occurs, and sufficient diffraction efficiency can be obtained.

(Refractive index of polymerizable monomer)

The polymerizable monomer has a refractive index at the wavelength of irradiated light (recording wavelength, etc.) to the hologram recording medium, usually 1.50 or more, preferably 1.52 or more, more preferably 1.55 or more, and usually 1.80 or less, preferably 1.78. It is as follows. If the refractive index is excessively small, the diffraction efficiency may not be sufficient and M/# may not be sufficient. If the refractive index is excessively large, the difference in refractive index with the resin matrix becomes too large, scattering increases, the transmittance decreases, and visibility decreases in the case of AR glass applications.

The refractive index shows a large value when evaluated at a short wavelength, but samples showing a relatively large refractive index at short wavelengths also show a relatively large refractive index at long wavelengths, and the relationship is never reversed. Therefore, the refractive index at a recording wavelength can be predicted by evaluating the refractive index at a wavelength other than the recording wavelength.

When the sample is a liquid, the refractive index of the polymerizable monomer can be measured by the minimum declination method, critical angle method, V block method, etc.

When the sample is a solid, the refractive index of the polymerizable monomer can be obtained by dissolving the compound in an appropriate solvent to form a solution, measuring the refractive index of this solution, and extrapolating the refractive index when the compound is 100%.

As a polymerizable monomer with a high refractive index, compounds having a halogen atom (iodine, chlorine, bromine, etc.) or a hetero atom (nitrogen, sulfur, oxygen, etc.) in the molecule are preferable. Among these, those having a heterocyclic structure are more preferable.

In order to ensure solubility in solvents and matrices, these compounds preferably have two or less heteroatoms in the heterocyclic ring structure contained in the molecule. By having two or less heteroatoms in the molecule, solubility is improved and a uniform recording layer can be obtained.

If the structural regularity of the heterocyclic ring in the molecule is high, coloring due to stacking or reduced solubility may occur. Among these, a heteroaryl group in which two or more rings are condensed is more preferable.

(compound i)

An example of a preferable polymerizable monomer includes compound i, which is a (meth)acrylic monomer represented by the following (formula a) and described in Japanese Patent Application Laid-Open No. 2010-018606.

[Formula 6]

In (formula a), A is a ring that may have a substituent. Ar is a (hetero)aryl group in which two or more rings are condensed, which may have a substituent, R ¹ is a hydrogen atom or a methyl group, and p is an integer of 1 to 7. When p is 2 or more, a plurality of Ar may be the same or different. However, in the case where A is an aromatic heterocycle and Ar is a heteroaryl group obtained by condensing two or more rings, which may have a substituent, in the structure in which each of A and Ar is connected, they are directly connected to each other, The partial structures in each structure of A and Ar do not contain heteroatoms.

Examples of the (meth)acrylic monomer represented by the above (formula a) include 2-(1-thianthrenyl)-1-phenyl(meth)acrylate, 2-(2-benzothiophenyl)-1- Phenyl (meth)acrylate, 2-(4-dibenzofuranyl)-1-phenyl (meth)acrylate, 2-(4-dibenzothiophenyl)-1-phenyl (meth)acrylate, 3-( 3-benzothiophenyl)-1-phenyl (meth)acrylate, 3-(4-dibenzofuranyl)-1-phenyl (meth)acrylate, 3-(4-dibenzothiophenyl)-1-phenyl (meth)acrylate, 4-(1-thianthrenyl)-1-phenyl(meth)acrylate, 4-(4-dibenzothiophenyl)-1-phenyl(meth)acrylate, 2,4-bis (1-thianthrenyl)-1-phenyl (meth)acrylate, 2,4-bis (2-dibenzothiophenyl)-1-phenyl (meth)acrylate, 2,4-bis (3-benzothio Phenyl)-1-phenyl (meth)acrylate, 2,4-bis (4-dibenzofuranyl)-1-phenyl (meth)acrylate, 2,4-bis (4-dibenzothiophenyl)-1 -Phenyl (meth)acrylate, 4-methyl-2,6-bis (1-thianthrenyl) -1-phenyl (meth)acrylate, 4-methyl-2,6-bis (2-benzothiophenyl) -1-phenyl (meth)acrylate, 4-methyl-2,6-bis (3-benzothiophenyl) -1-phenyl (meth)acrylate, 4-methyl-2,6-bis (4-dibenzo) furanyl)-1-phenyl (meth)acrylate, 4-methyl-2,6-bis (4-dibenzothiophenyl)-1-phenyl (meth)acrylate, etc.

These (meth)acrylic monomers have a high degree of freedom in design and are industrially advantageous as component (c).

(compound ii)

As another preferred example of the polymerizable monomer, compound ii described in Japanese Patent Application Laid-Open No. 2016-222566 and represented by at least the following formula (1) can be mentioned.

[Formula 7]

In formula (1), Q is a thiophene ring sulfide group which may have a substituent. G is an acryloyl or methacryloyl group. L is an r + s valent linking group or direct bond connecting Q and G, which may have a substituent. r represents an integer between 1 and 5. s represents an integer between 1 and 5.

Hereinafter, compound ii represented by the above formula (1) will be described.

<About L in equation (1)>

L is an arbitrary linking group of r + s value connecting Q and G, which may have a substituent, or a direct bond. In order to provide a high refractive index, L is preferably a group derived from a cyclic compound. In order to provide compatibility, L is preferably a group derived from an aliphatic compound. These structures may be combined according to the purpose of the material, and may have a linking group selected from -O-, -S-, -CO-, -COO-, and -CONH- between the C-C bonds.

In order to improve the compatibility of the entire compound, L is preferably an aliphatic hydrocarbon group having 2 to 18 carbon atoms, preferably 3 to 6 carbon atoms. In order to maintain high compatibility while keeping the size of the entire compound small, L is preferably a chain-shaped or cyclic saturated hydrocarbon group, and more preferably a hydrocarbon group having a branched structure.

Examples of the straight chain saturated hydrocarbon group include methylene group, ethylene group, n-propylene group, cyclopropylene group, n-butylene group, n-pentylene group, and n-hexylene group. Hydrocarbon groups having a branched structure include, for example, isopropylene group, isobutylene group, s-butylene group, t-butylene group, 1,1-dimethyl-n-propylene group, and 1,2-dimethyl-n-propylene group. , 2,2-dimethyl-n-propylene group, 1-ethyl-n-propylene group, 1-methyl-n-butylene group, 2-methyl-n-butylene group, 3-methyl-n-butylene group, 1, 1,2-trimethyl-n-propylene group, 1,2,2-trimethyl-n-propylene group, 1-ethyl-2-methyl-n-propylene group, 1,1-dimethyl-n-butylene group, 2, 2-dimethyl-n-butylene group, 3,3-dimethyl-n-butylene group, 1,2-dimethyl-n-butylene group, 1,3-dimethyl-n-butylene group, 2,3-dimethyl-n- Butylene group, 1-ethyl-n-butylene group, 2-ethyl-n-butylene group, 1-methyl-n-pentylene group, 2-methyl-n-pentylene group, 3-methyl-n-pentylene group, 4- A methyl-n-pentylene group, etc. can be mentioned. Examples of the cyclic hydrocarbon group include cyclohexylene group and cyclopentylene group.

In order to increase the refractive index of the entire compound, L is preferably a 3- to 8-membered cyclic compound, and more preferably a 5- to 6-membered cyclic compound. The ring possessed by L may be a single ring structure or a condensed ring structure. The number of rings constituting L is 1 to 4, preferably 1 to 3, and more preferably 1 to 2. Aromaticity is not necessarily required for the ring constituting L, but in order to maintain a high refractive index while keeping the size of the entire molecule small, it is preferable that it contains an unsaturated bond, and it is also preferable that it is an aromatic hydrocarbon ring group or an aromatic heterocyclic ring group. do. In order to ensure light transparency during hologram recording and reproduction, it is preferable that it has little coloring, and in this regard, it is more preferable that it is an aromatic hydrocarbon ring group.

The aromatic hydrocarbon ring constituting L preferably has 6 to 14 carbon atoms, such as a benzene ring, indene ring, naphthalene ring, azulene ring, fluorene ring, acenaphthylene ring, anthracene ring, phenanthrene ring, or pyrene ring. includes 6 to 12 aromatic hydrocarbon rings. From the viewpoint of avoiding coloring and ensuring solubility, an aromatic hydrocarbon ring having 6 to 10 carbon atoms, such as a benzene ring or a naphthalene ring, is particularly preferable.

When the ring constituting L is an aromatic heterocyclic ring, the hetero atom is not particularly limited, and each atom such as S, O, N, or P can be used. In terms of ensuring compatibility, each atom of S, O, and N is preferred. From the viewpoint of avoiding coloring and ensuring solubility, it is preferable that the number of heteroatoms is 1 to 3 in the molecule.

The aromatic heterocycle constituting L specifically includes a furan ring, a thiophene ring, a pyrrole ring, an imidazole ring, a triazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, Oxazole ring, thiazole ring, benzofuran ring, benzothiophene ring, indole ring, isoindole ring, benzoimidazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, dibenzofuran ring, dibenzothiophene ring , aromatic heterocyclic rings having 2 to 18 carbon atoms, preferably 3 to 6 carbon atoms, such as carbazole ring, thiantrene ring, dibenzothioxane ring, dibenzobenzothiophene ring, oxazolidine ring, and thiazolidine ring. You can. In order to maintain a high refractive index while keeping the size of the entire compound small, a thiophene ring, a furan ring, and a pyrrole ring are preferred.

<Substituents that L may have>

L may further have a substituent other than the above. For example, in order to further improve solubility, it may have an alkyl group, an alkoxy group, an alkoxyalkyl group, an alkoxycarbonyl group, an alkoxyalkoxy group, or an alkanoyloxy group as a substituent. In order to increase the refractive index, it may have an aryl group, an alkylthio group, an alkylthioalkyl group, an aryloxy group, or an arylalkoxyl group as a substituent. In order to achieve economical synthesis, it is preferable to be unsubstituted.

Here, the alkyl group is preferably a chain alkyl group having 1 to 4 carbon atoms, and specifically includes methyl group, ethyl group, n-propyl group, isopropyl group, s-butyl group, isobutyl group, s-butyl group, etc. there is.

The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, and specific examples include a methoxy group and an ethoxy group.

The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 6 carbon atoms, and specifically, methoxymethyl group, ethoxymethyl group, propoxymethyl group, butoxymethyl group, methoxyethyl group, ethoxyethyl group, propoxyethyl group, and butoxyethyl group. etc. can be mentioned.

The alkoxycarbonyl group is preferably an alkoxycarbonyl group having 2 to 5 carbon atoms, and specific examples include methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, and butoxycarbonyl group.

The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 3 to 6 carbon atoms, and specific examples include methoxyethoxy group, ethoxyethoxy group, propoxyethoxy group, and butoxyethoxy group.

The alkanoyloxy group is preferably an alkanoyloxy group having 2 to 5 carbon atoms, and specific examples include acetoxy group, propionoxy group, butyloxy group, and valerooxy group.

The aryl group is preferably an aryl group consisting of a single ring or fused ring having 6 to 14 carbon atoms, and specific examples include a phenyl group, a naphthyl group, and anthranyl group.

The alkylthio group is preferably an alkylthio group having 2 to 4 carbon atoms, and specific examples include methylthio group, ethylthio group, n-propylthio group, and isopropylthio group.

The alkylthioalkyl group is preferably an alkylthioalkyl group having 2 to 4 carbon atoms, and specific examples include methylthiomethyl group, methylthioethyl group, ethylthiomethyl group, and ethylthioethyl group.

An aryloxy group is an aryloxy group consisting of a single ring or a condensed ring having 6 to 14 carbon atoms, and specific examples include a phenoxy group.

An arylalkoxy group is an arylalkoxy group having 7 to 5 carbon atoms, and specific examples include a benzyloxy group.

<About Q in equation (1)>

Q is a thiophene-containing ring sulfide group that may have a substituent, and is preferably a thiophene-containing ring sulfide group represented by the following formula (2) or (3).

[Formula 8]

In formulas (2) and (3), the sulfide group may be bonded to the thiophene ring at any position. Q is a central group for increasing the refractive index of the compound represented by formula (1), and it is preferable that Q alone has a high refractive index structure.

The refractive index of Q alone can be estimated using the atomic group contribution method. Calculate n = {(1 + 2[R]/V ₀ )/(1 - [R]/V ₀ )} ^0.5 using molecular refraction [R] and molar volume V ₀ for each atomic group constituting the compound, It can be estimated by taking the sum.

Q has a shorter absorption wavelength of light, and from the viewpoint of less coloring by visible light, a dibenzothiophene ring represented by formula (2) is more preferable in applications requiring transparency.

It is preferable that Q has a somewhat large molecular weight from the viewpoint of reducing shrinkage due to crosslinking upon light irradiation. The molecular weight of the Q portion is usually 50 or more, preferably 70 or more. From the viewpoint of ensuring mobility during optical recording, the molecular weight of the Q portion is usually 300 or less, preferably 250 or less.

<Substituents that Q may have>

Q may further have a substituent. The substituents that Q may have are not particularly limited as long as they do not reduce compatibility or do not reduce the refractive index. Specifically, alkylthio groups with 1 to 3 carbon atoms, such as a methylthio group, and alkylthioalkyl groups with 2 to 6 carbon atoms, such as a methylthiomethyl group, can be mentioned.

<About G in equation (1)>

G represents an acryloyl group or a methacryloyl group.

<About the binding position of L and Q>

When L is a cyclic group, the preferred substitution position of Q for L may be any position when r is 1, and when r is 2 or more, it is preferable that they are not adjacent to each other for the reason of high synthesis yield.

When L is a heteroaryl ring group, it is preferable that the partial structure in the structure of L and Q, which are directly connected to each other, does not contain a hetero atom. In other words, in the structure in which L and Q are connected, it is preferable that the partial structures containing heteroatoms in the structure of L and Q are not directly connected to each other. Among the structures of L and Q, structures in which substructures containing heteroatoms are directly connected are prone to absorption in the visible light region, and this coloration is highly likely to interfere with light transmission during recording and playback, so it is not desirable. not.

<about r and s>

r is an integer of 1 to 5, and when r is 2 or more, the plurality of Qs may be the same or different. In order to obtain good solubility with a solvent or matrix, r is preferably 1 to 3, and more preferably 2 or 3.

s represents an integer from 1 to 5, and is preferably 1 in order to suppress shrinkage due to photocuring to a low level.

<Example compounds>

Specific examples of compound ii are given below. Compound ii is not limited to the examples below.

[Formula 9]

[Formula 10]

[Formula 11]

Compound ii is, as shown in the structural formula above, S-4-dibenzothiophenylthioacrylate, S-7-benzothiophenylthioacrylate, S-(1,3-diphenyl)-4-dibenzothio Phenylthioacrylate, S-(1,3-diphenyl)-7-benzothiophenylthioacrylate, 6-phenyl-2,4-bis(4-dibenzothiophenyl)-1-phenylacrylate, 6 -Phenyl-2,4-bis(7-benzothiophenyl)-1-phenylacrylate, 7-(3-(4-dibenzothiophenyl)-2,6-dioxa-[3,3,0] Bicyclooctyl)acrylate, 7-(3-(7-benzothiophenyl)-2,6-dioxa-[3,3,0]bicyclooctyl)acrylate, 2,4-bis(4-di Benzothiophenyl)-1-cyclohexyl acrylate, 2,4-bis(7-benzothiophenyl)-1-cyclohexyl acrylate, 3,3-bis(4-dibenzothiophenylthio)methylphenylacrylate, 3,3-bis(7-benzothiophenylthio)methylphenylacrylate, 4-(1,2-bis(4-dibenzothiophenylthio)ethylphenylacrylate, 4-(1,2-bis(7- Benzothiophenylthio)ethylphenylacrylate, 2,3-bis(4-dibenzothiophenylthio)propyl acrylate, 2,3-bis(7-benzothiophenylthio)propyl acrylate, 2-(4- Dibenzothiophenylthio)ethyl acrylate, 2-(7-benzothiophenylthio)ethyl acrylate, 1,3-bis(4-dibenzothiophenylthio)-2-propyl acrylate, 1,3-bis (7-benzothiophenylthio)-2-propylacrylate, 2,2-bis(4-dibenzothiophenylthiomethyl)-3-(4-dibenzothiophenylthio)propyl acrylate, etc. .

The composition for a hologram recording medium of the present invention may contain only one type of compound i or compound ii as component (c), or may contain two or more types.

(Molar extinction coefficient of polymerizable monomer)

The polymerizable monomer preferably has a molar extinction coefficient of 100 L·mol ^-1 ·cm ^-1 or less at the recording wavelength of the hologram. When the molar extinction coefficient is 100 L·mol ^-1 ·cm ^-1 or less, the transmittance of the medium is prevented from being lowered, and sufficient diffraction efficiency can be obtained for the thickness.

(Molar extinction coefficient of polymerizable monomer)

The polymerizable monomer preferably has a molar extinction coefficient of 100 L·mol ^-1 ·cm ^-1 or less at the recording wavelength of the hologram. When the molar extinction coefficient is 100 L·mol ^-1 ·cm ^-1 or less, the transmittance of the medium is prevented from being lowered, and sufficient diffraction efficiency can be obtained for the thickness.

＜Component (d)＞

A photopolymerization initiator refers to something that generates a cation, anion, or radical that causes a chemical reaction by light, and contributes to the polymerization of the polymerizable monomer described above. The type of photopolymerization initiator is not particularly limited and can be appropriately selected depending on the type of polymerizable monomer, etc.

As a photopolymerization initiator, the oxime ester photopolymerization initiator illustrated below or other photopolymerization initiators other than the oxime ester photopolymerization initiator can be used, but it is preferable to use at least one type of oxime ester photopolymerization initiator. do.

In this case, it is preferable to use 0.003% by weight or more of the oxime ester-based photopolymerization initiator, more preferably 0.03% by weight or more, further preferably 0.05% by weight or more, especially preferably, based on the total amount of the photopolymerization initiator. is 0.1 to 100% by weight.

Other photopolymerization initiators include a cationic photopolymerization initiator, an anionic photopolymerization initiator, and a radical photopolymerization initiator described later. Among other photopolymerization initiators, it is preferable to use a radical photopolymerization initiator because it is difficult to inhibit the reaction that forms the matrix, and among these, a phosphine oxide compound is more preferable.

As a photopolymerization initiator, a compound having a molar extinction coefficient of 1000 L·mol ^-1 ·cm ^-1 or less at the recording wavelength is particularly preferable. By having a molar extinction coefficient of 1000 L·mol ^-1 ·cm ^-1 or less, a decrease in the transmittance of the hologram recording medium at the recording wavelength that occurs when mixing an amount that can obtain sufficient diffraction efficiency can be suppressed. .

(Oxime ester-based photopolymerization initiator)

The oxime ester photopolymerization initiator only has -C=N-O- in part of the structure, and among them, the compound represented by the following (formula d) or (formula f) is preferable because it has excellent recording sensitivity.

[Formula 12]

In (formula d), X is a single bond; Alkylene group having 1 to 20 carbon atoms which may have a substituent, alkenylene group -(CH=CH) _n - which may have a substituent, alkynylene group -(C≡C) _n - which may have a substituent, and these A divalent group selected from the group consisting of a combination (n represents an integer from 1 to 5); represents.

R ² represents a monovalent organic group containing an aromatic ring and/or a heteroaromatic ring.

R ³ is a hydrogen atom or an alkylthio group with 1 to 12 carbon atoms, an alkoxycarbonyl group with 2 to 12 carbon atoms, an alkenyloxycarbonyl group with 3 to 12 carbon atoms, or an alkynyloxy group with 3 to 12 carbon atoms, each of which may have a substituent. Carbonyl group, aryloxycarbonyl group with 7 to 12 carbon atoms, heteroaryloxycarbonyl group with 3 to 12 carbon atoms, alkylthiocarbonyl group with 2 to 12 carbon atoms, alkenylthiocarbonyl group with 3 to 12 carbon atoms, alkynylthiocarbonyl group with 3 to 12 carbon atoms, Arylthiocarbonyl group having 7 to 12 carbon atoms, heteroarylthiocarbonyl group having 3 to 12 carbon atoms, alkylthioalkoxy group, -ON=CR ³² R ³³ , -N(OR ³⁴ )-CO-R ³⁵ and the following (formula e) The groups represented (R ³² and R ³³ , and R ³⁴ and R ³⁵ each represent an optionally substituted alkyl group having 1 to 12 carbon atoms and may be different from each other).

[Formula 13]

In (formula e), R ³⁰ and R ³¹ each independently represent an optionally substituted alkyl group having 1 to 12 carbon atoms.

R ⁴ is an alkanoyl group with 2 to 12 carbon atoms, an alkenoyl group with 3 to 25 carbon atoms, a cycloalkanoyl group with 3 to 8 carbon atoms, an aryloyl group with 7 to 20 carbon atoms, or an alkanoyl group with 3 to 20 carbon atoms, each of which may be substituted. represents a group selected from the group consisting of a heteroaryloyl group, an alkoxycarbonyl group having 2 to 10 carbon atoms, and an aryloxycarbonyl group having 7 to 20 carbon atoms.

[Formula 14]

In (formula f), R ⁵ is a hydrogen atom; an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 25 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms, or a heteroarylalkyl group having 4 to 25 carbon atoms, which may have a substituent; Or it represents a group that combines with Y ¹ or Z to form a ring.

R ⁶ is an alkanoyl group of 2 to 20 carbon atoms, an alkenoyl group of 3 to 25 carbon atoms, a cycloalkanoyl group of 4 to 8 carbon atoms, an aryloyl group of 7 to 20 carbon atoms, an alkoxycarbonyl group of 2 to 10 carbon atoms, or a carbon number of 7. It represents an aryloxycarbonyl group with 2 to 20 carbon atoms, a heteroaryl group with 2 to 20 carbon atoms, a heteroaryloyl group with 3 to 20 carbon atoms, or an alkylaminocarbonyl group with 2 to 20 carbon atoms, and all of them may have a substituent.

Y ¹ represents a divalent aromatic hydrocarbon group and/or an aromatic heterogroup formed by condensation of two or more rings, which may have a substituent.

Z represents an aromatic group which may have a substituent.

Specific examples of the oxime ester photopolymerization initiator include 1-(9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl)-1-(O-benzoyloxime)methyl glutarate. , 1-(9-ethyl-6-cyclohexanoyl-9H-carbazol-3-yl)-1-(O-acetyloxime)methyl glutarate, 1-(9-ethyl-6-diphenylamino- 9H-carbazol-3-yl)-1-(O-acetyloxime)hexane, 1-(9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl)-1-(O -Acetyloxime)ethanone, 1-(9-ethyl-6-benzoyl-9H-carbazol-3-yl)-1-(O-acetyloxime)ethanone, 1-(9-ethyl-6-(2) -Methylbenzoyl)-9H-carbazol-3-yl)-1-(O-chloroacetyloxime)methyl glutarate, 1-(9-ethyl-9H-carbazol-3-yl)-1-(O -Acetyloxime)-3,3-dimethylbutanoic acid, 1-(9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl)-1-(O-acetyloxime)glutaric acid Ethyl, 1-(4-(phenylthio)-2-(O-benzoyloxime))-1,2-octanedione or compounds described in JP2010-8713, JP2009-271502, etc. can be mentioned.

Among the compounds represented by the above (formula d) or (formula f), those having a ketoxime structure are more preferable.

(Preferred oxime ester photopolymerization initiator)

Among the oxime ester photopolymerization initiators, it is particularly preferable to use a compound represented by the following formula (4) (hereinafter sometimes referred to as “compound (4)”).

[Formula 15]

In formula (4), R ²¹ represents an alkyl group. R ²² represents any of an alkyl group, an aryl group, and an aralkyl group. R ²³ represents -(CH ₂ ) _m - group. m represents an integer of 1 to 6. R ²⁴ represents a hydrogen atom or an arbitrary substituent. R ²⁵ represents an arbitrary substituent that does not have a multiple bond conjugated to the carbonyl group to which it is bonded.

Compound (4) has an advantage that the transmittance does not decrease even when irradiated with light after recording because R ²⁵ in the formula (4) is not conjugated with a carbonyl group. Compound (4) has the advantage that, in a hologram recording medium as a memory, the transmission speed does not decrease even if reproduction is repeated, and in an AR glass light guide plate application, it does not color even when used outdoors.

Hereinafter, each group in formula (4) will be described in detail.

<R ²¹ >

R ²¹ represents an alkyl group. When R ²¹ is, for example, other than an alkyl group such as an aromatic ring group, the sp ² property of the nitrogen atom to which R ²¹ is bonded increases, and the conjugation from the carbazole ring of formula (4) to R ²¹ is extended, Light emission occurs due to decomposition products after light irradiation. Therefore, R ²¹ is preferably an alkyl group that does not have such a conjugated system.

The alkyl group for R ²¹ is methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, cyclopentyl, hexyl, and cyclo. Hexyl group, heptyl group, octyl group, 2-ethylhexyl group, 3,5,5-trimethylhexyl group, decyl group, dodecyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclopropylmethyl group , cyclohexylmethyl group, 4-butylmethylcyclohexyl group, and other straight-chain, branched-chain, and cyclic alkyl groups. Among these, the carbon number is preferably 1 or more, more preferably 2 or more, preferably 18 or less, more preferably 8 or less, especially a straight chain alkyl group with a carbon number in the range of 1 to 4. Compound ( 4) is preferable in terms of crystallinity.

The alkyl group of R ²¹ may have a substituent. Substituents that may be included include an alkoxy group, a dialkylamino group, a halogen atom, an aromatic ring group, and a heterocyclic group. Among these, an alkoxy group is preferable from the viewpoint of ease of controlling the solubility of the compound.

Preferred alkoxy groups include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, cyclopentyl group, and cyclohexyl group.

Additionally, an alkyl group substituted with a fluorine atom is preferable because water repellency increases and the water resistance of the compound is improved.

<R ²² >

R ²² represents any of an alkyl group, an aryl group, and an aralkyl group. R ²² is a radical moiety generated when the photopolymerization initiator is irradiated with light, and is preferably an alkyl group with a small molecular weight from the viewpoint of ease of movement of the radical in the composition for hologram recording media.

Specific examples of the alkyl group of R ²² have the same meaning as the above-mentioned R ²¹ , and the substituents it may have have the same meaning. Among these, the number of carbon atoms is preferably 1 or more and 4 or less, and more preferably 2 or less in terms of radical mobility.

From the viewpoint of improving the water resistance of compound (4), R ²² is preferably an aryl group.

Specific examples of the aryl group for R ²² include phenyl group, naphthyl group, anthryl group, and indenyl group. In terms of radical mobility, a phenyl group is preferable.

Specific examples of the aralkyl group for R ²² include benzyl group, phenethyl group, and naphthylmethyl group. Radicals such as benzyl group and naphthylmethyl group are preferred because they are expected to exhibit unique reactivity.

Substituents for the aryl ring portion of the aryl group or aralkyl group of R ²² include an alkyl group, a halogen atom, an alkoxy group, etc., but unsubstitution is preferable from the viewpoint of radical mobility.

<R ²³ and m>

R ²³ represents -(CH ₂ ) _m - group. When R ²³ is a substituent capable of conjugating with the carbazole ring of formula (4), the conjugation of R ²³ extends from the carbazole ring, so the absorption wavelength of the photopolymerization initiator becomes longer. Therefore, R ²³ is preferably a -(CH ₂ ) _m - group that does not have such a conjugation system.

Additionally, m represents an integer of 1 to 6. Among these, it is preferably 2 or more and 4 or less. When m is in the above preferable range, the electronic effect of the substituent R ²⁴ substituted before it tends to be easily reflected.

<R ²⁴ >

R ²⁴ represents a hydrogen atom or an arbitrary substituent. The optional substituent is not particularly limited as long as it does not impair the effect of the present invention, and includes an alkyl group, an alkoxycarbonyl group, a monoalkylaminocarbonyl group, a dialkylaminocarbonyl group, an aromatic ring group, and a heterocyclic group.

Among these, R ²⁴ is preferably any of an alkyl group, an alkoxycarbonyl group, an aromatic ring group, or a heterocyclic group from the viewpoint of ease of obtaining raw materials and synthesis, and an alkoxycarbonyl group is particularly preferable from the viewpoint of exhibiting a remote electronic effect.

Specific examples of the alkyl group of R ²⁴ have the same meaning as that of R ²¹ described above, and the substituents it may have have the same meaning. Among these, the carbon number is preferably 1 or more and 8 or less, and more preferably 4 or less from the viewpoint of adjusting the solubility of the compound.

Examples of the alkoxycarbonyl group for R ²⁴ include methoxycarbonyl group, ethoxycarbonyl group, and isopropoxycarbonyl group, and the number of carbon atoms is preferably 2 or more and 19 or less, and more preferably 7 or less for adjusting the solubility of the compound. It is desirable in that respect.

The alkoxycarbonyl group may have a substituent, and examples of the substituent it may have include an alkoxy group, a dialkylamino group, and a halogen atom. Among these, an alkoxy group is preferable from the viewpoint of ease of solubility adjustment.

Specific examples of the alkyl group portion of the monoalkylaminocarbonyl group or dialkylaminocarbonyl group for R ²⁴ have the same meaning as the alkyl group for R ²¹ described above, and the substituents they may have have the same meaning. Among these, the carbon number of the alkyl group portion bonded to the amino group is preferably 1 or more and 8 or less, and more preferably 4 or less. When the carbon number of the alkyl group portion bonded to the amino group is within the above preferable range, solubility tends to be obtained.

The aromatic ring group for R ²⁴ includes a single ring or fused ring such as a phenyl group, naphthyl group, or anthryl group. Among these, the number of carbon atoms is 6 or more, preferably 20 or less, and more preferably 10 or less from the viewpoint of the solubility of the compound.

The aromatic ring group may have a substituent, and examples of the substituent it may have include an alkyl group, an alkoxy group, a dialkylamino group, and a halogen atom. Among these, an alkyl group is preferable from the viewpoint of ease of solubility adjustment.

Preferred alkyl groups include methyl group, ethyl group, isopropyl group, cyclohexyl group, isobutyl group, 2-ethylhexyl group, and n-octyl group.

The heterocyclic group for R ²⁴ is preferably a group containing at least a heterocyclic structure having one or more heteroatoms in the ring. The heteroatom contained in the heterocyclic group is not particularly limited, and each atom such as S, O, N, or P can be used. In terms of availability of raw materials and ease of synthesis, each of S, O, and N atoms is preferable.

The heterocyclic group for R ²⁴ specifically includes thienyl group, furyl group, pyranyl group, pyrrolyl group, pyridyl group, pyrazolyl group, thiazolyl group, thiadiazolyl group, quinolyl group, dibenzothiophenyl group, and benzoyl group. Single or condensed rings such as thiazolyl group can be mentioned. Among these, the number of carbon atoms is 1 or more, more preferably 2 or more, preferably 10 or less, and more preferably 5 or less, from the viewpoint of ease of obtaining raw materials and synthesis.

The heterocyclic group may have a substituent, and examples of the substituent it may have include an alkyl group, an alkoxy group, a dialkylamino group, and a halogen atom. Among these, an alkyl group is preferable from the viewpoint of ease of solubility adjustment.

Preferred alkyl groups include methyl group, ethyl group, isopropyl group, cyclohexyl group, isobutyl group, 2-ethylhexyl group, and n-octyl group.

<R ²⁵ >

R ²⁵ represents an arbitrary substituent that does not have a multiple bond conjugated to the carbonyl group to which it is bonded. These groups prevent the conjugated system from extending beyond the carbazole ring. Therefore, since the conjugate system of the decomposition remains generated after light irradiation does not become long, the absorption wavelength of the decomposition products does not become longer. Thereby, the effect of suppressing absorption after recording is obtained.

Examples of R ²⁵ include an alkyl group, an alkoxy group, a dialkylamino group, an alkylsulfonyl group, and a dialkylaminosulfonyl group. Among these, an alkyl group is preferable from the viewpoint of compound stability.

Specific examples of the alkyl group of R ²⁵ have the same meaning as that of R ²¹ described above, and the substituents it may have have the same meaning. Among these, the number of carbon atoms is preferably 1 or more, more preferably 2 or more, preferably 18 or less, more preferably 10 or less, and a branched alkyl group is preferable from the viewpoint of ease of production of the compound. . Specifically, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, isopropyl group, tert-butyl group, adamantyl group, and 1-ethylpentyl group are particularly preferred.

Specific examples of the alkoxy group, dialkylamino group, alkylsulfonyl group, and alkyl portion of the dialkylaminosulfonyl group for R ²⁵ have the same meaning as those for R ²¹ described above, and the substituents that may be present have the same meaning. Among these, the number of carbon atoms is preferably 3 or more and 18 or less, and more preferably 8 or less in terms of crystallinity of the compound.

The absorption wavelength range of compound (4) is preferably 340 nm or more, more preferably 350 nm or more, preferably 700 nm or less, and more preferably 650 nm or less. For example, when the light source is a blue laser, it is desirable to have absorption at least at 350 to 430 m. In the case of a green laser, it is desirable to have absorption in at least 500 to 550 nm. When the absorption wavelength range is different from the above-mentioned range, it becomes difficult to efficiently use the irradiated light energy for a photopolymerization reaction, so sensitivity tends to decrease.

Compound (4) preferably has a molar extinction coefficient of 10 L·mol ^-1 ·cm ^-1 or more, and more preferably 50 L·mol ^-1 ·cm ^-1 or more at the recording wavelength of the hologram. This molar extinction coefficient is preferably 20,000 L·mol ^-1 ·cm ^-1 or less, and more preferably 10,000 L·mol ^-1 ·cm ^-1 or less. When the molar extinction coefficient is within the above range, effective recording sensitivity can be obtained, the transmittance of the medium is prevented from being excessively low, and sufficient diffraction efficiency for the thickness tends to be obtained.

The solubility of compound (4) in component (a-1) and component (b-1) under the conditions of 25°C and 1 atm is preferably 0.01% by weight or more, and more preferably 0.1% by weight or more. desirable.

Among commonly used oxime ester-based initiators, those having the above-mentioned absorption maximum are generally materials constituting component (a-1) and component (b-1) such as isocyanates and polyols, and (meth)acrylic acid. The solubility of components (c-1) such as esters is often poor. Since compound (4) has excellent solubility in components (a-1) to (c-1) such as isocyanates, polyols, and (meth)acrylic acid esters, it can be preferably used in a composition for hologram recording media. .

Specific examples of the photopolymerization initiator represented by compound (4) are shown below, but are not limited thereto.

[Formula 16]

[Formula 17]

[Formula 18]

[Formula 19]

The synthesis method for compound (4) is not particularly limited, and it can be produced by a combination of general synthesis methods. Specifically, the method described in International Publication No. 2009/131189 and the like can be mentioned.

For example, as shown in the following chemical formula, an acyl group containing R ⁵ , R ⁴ and R ³ can be introduced into the carbazole ring by the Flipel Crafts reaction. Regarding the Flidel Crafts reaction,

Andrew Streitwieser. Jr. et. al, Introduction to Organic Chemistry, Macmillan Publishing Company, NewYork, P652-653,

and

Bradford p. Mundy et. al., Name Reactions and Reagents in Organic Synthesis, AWiley-Interscience Publication, P82-83

It is listed in etc.

[Formula 20]

Nitrogenation to methylene is possible using nitrous acid or nitrite ester.

Acylation of the hydroxyl group can be performed using a corresponding acid halide, anhydride, and base.

Nitsorination and acylation represented by the following chemical formulas are also described in Japanese Patent Publication No. 2004-534797, Organic Reaction Volume VII, KRIEGER PUBLISHING COMPANY MALABAR, Florida, Chapter 6, etc.

[Formula 21]

Said R ²¹ to R ²⁵ have the same meaning as R ²¹ to R ²⁵ in formula (4).

(Cationic photopolymerization initiator)

Any cationic photopolymerization initiator can be used as long as it is a known cationic photopolymerization initiator. Examples include aromatic onium salts. Specific examples of aromatic onium salts include anionic components such as SbF ₆ ^- , BF ₄ ^- , AsF ₆ ^- , PF ₆ ^- , CF ₃ SO ₃ ^- , B(C ₆ F ₅ ) ₄ ^- , iodine, sulfur, A compound consisting of an aromatic cation component containing atoms such as nitrogen and phosphorus can be mentioned. Among them, diaryliodonium salt, triaryl sulfonium salt, etc. are preferable. The cationic photopolymerization initiator illustrated above may be used individually, or two or more types may be used together in any combination and ratio.

(Anionic photopolymerization initiator)

Any anionic photopolymerization initiator can be used as long as it is a known anionic photopolymerization initiator. Examples include amines. Examples of amines include amino group-containing compounds such as dimethylbenzylamine, dimethylaminomethylphenol, and 1,8-diazabicyclo[5.4.0]undecen-7, and derivatives thereof; Imidazole compounds such as imidazole, 2-methylimidazole, and 2-ethyl-4-methylimidazole, and derivatives thereof; etc. can be mentioned. The anionic photopolymerization initiator exemplified above may be used individually, or two or more types may be used together in any combination and ratio.

(Radical photopolymerization initiator)

Any radical photopolymerization initiator can be used as long as it is a known radical photopolymerization initiator. Examples include phosphine oxide compounds, azo compounds, azide compounds, organic peroxides, organic borate salts, onium salts, bisimidazole derivatives, titanocene compounds, iodonium salts, organic thiol compounds, halogenated hydrocarbon derivatives, etc. The radical photopolymerization initiator exemplified above may be used individually, or two or more types may be used together in any combination and ratio. As described above, among these, phosphine oxide compounds are preferable.

There is no particular limitation on the type of the phosphine oxide compound as long as it does not impair the purpose and effect of the present invention, but an acylphosphine oxide compound is preferable among them.

Examples of the acylphosphine oxide compound include monoacylphosphine oxide represented by the following (formula b), or diacylphosphine oxide represented by the following (formula c). Any one of these may be used individually, and two or more types may be used together in any combination and ratio.

[Formula 22]

In (formula b), R ⁷ is an alkyl group having 1 to 18 carbon atoms; An alkyl group with 1 to 4 carbon atoms, a cycloalkyl group with 5 to 8 carbon atoms, a phenylalkyl group with 7 to 9 carbon atoms, a phenyl group, a naphthyl group, or a biphenyl group substituted with a halogen or an alkoxy group with 1 to 6 carbon atoms; A phenyl group, naphthyl group, or biphenyl group substituted with at least one selected from the group consisting of halogen, an alkyl group with 1 to 12 carbon atoms, and an alkoxy group with 1 to 12 carbon atoms; A group of a 5- or 6-membered heterocyclic ring containing monovalent N, O or S; represents.

R ⁸ is a phenyl group; Naphthyl group; Biphenyl group; A phenyl group, naphthyl group, or biphenyl group substituted with at least one selected from the group consisting of halogen, an alkyl group with 1 to 12 carbon atoms, and an alkoxy group with 1 to 12 carbon atoms; A group of a 5- or 6-membered heterocyclic ring containing monovalent N, O or S; Alkoxy group having 1 to 18 carbon atoms; Phenoxy group; Phenoxy group, benzyloxy group, cyclohexyloxy group substituted with halogen, alkyl group with 1 to 4 carbon atoms, or alkoxy group with 1 to 4 carbon atoms; represents. R ⁸ and R ⁷ may be combined with the phosphorus atom to form a ring.

R ⁹ is an alkyl group having 1 to 18 carbon atoms; Alkyl group with 1 to 4 carbon atoms, cycloalkyl group with 5 to 8 carbon atoms, phenylalkyl group with 7 to 9 carbon atoms, phenyl group, naphthyl group, biphenyl group substituted with halogen or alkoxy group with 1 to 6 carbon atoms; A phenyl group, naphthyl group, or biphenyl group substituted with at least one selected from the group consisting of halogen, an alkyl group having 1 to 12 carbon atoms, and an alkoxy group having 1 to 12 carbon atoms; A group of a 5- or 6-membered heterocyclic ring containing monovalent N, O or S; Or, a group represented by the following (formula b-1); am.

[Formula 23]

In (formula b-1), B ¹ is an alkylene group or cyclohexylene group having 2 to 8 carbon atoms; A phenylene group or biphenylene group that is unsubstituted or substituted with a halogen, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms; represents.

R ^7' and R ^8' represent the same groups as those described for R ⁷ and R ⁸ in (formula b) described above.

In the molecules represented by (formula b) and (formula b-1), R ⁷ and R ^7' , R ⁸ and R ^8' may be the same or different.

[Formula 24]

In (formula c), R ¹⁰ is an alkyl group having 1 to 18 carbon atoms; An alkyl group with 1 to 4 carbon atoms, a cycloalkyl group with 5 to 8 carbon atoms, a phenylalkyl group with 7 to 9 carbon atoms, a phenyl group, a naphthyl group, or a biphenyl group substituted with a halogen or an alkoxy group with 1 to 6 carbon atoms; A phenyl group, naphthyl group, or biphenyl group substituted with at least one selected from the group consisting of halogen, an alkyl group with 1 to 12 carbon atoms, and an alkoxy group with 1 to 12 carbon atoms; A 5- or 6-membered heterocyclic group containing monovalent N, O or S, an alkoxy group with 1 to 18 carbon atoms, or a phenoxy group; A phenoxy group, benzyloxy group, or cyclohexyloxy group substituted with halogen, an alkyl group with 1 to 4 carbon atoms, or an alkoxy group with 1 to 4 carbon atoms; represents.

R ¹¹ and R ¹² are independently an alkyl group having 1 to 18 carbon atoms; An alkyl group with 1 to 4 carbon atoms, a cycloalkyl group with 5 to 8 carbon atoms, a phenylalkyl group with 7 to 9 carbon atoms, a phenyl group, a naphthyl group, or a biphenyl group substituted with a halogen or an alkoxy group with 1 to 6 carbon atoms; A phenyl group, naphthyl group, or biphenyl group substituted with at least one selected from the group consisting of halogen, an alkyl group with 1 to 12 carbon atoms, and an alkoxy group with 1 to 12 carbon atoms; A group of a 5- or 6-membered heterocyclic ring containing monovalent N, O or S; represents.)

＜Component (e)＞

Component (e) is a compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group. When the composition for a hologram recording medium of the present invention contains component (e), the isocyanate-reactive functional group of component (e) reacts with the isocyanate group of component (a), or the isocyanate group of component (e) reacts with the isocyanate group of component (b). By reacting with an isocyanate-reactive functional group, it is immobilized in the resin matrix, and recording sensitivity can be improved and high M/# realized by the nitroxyl radical group contained in component (e).

Examples of the isocyanate-reactive functional group of component (e) include the same isocyanate-reactive functional group of component (b).

Below, components (e-1) to (e-4), which are each component (e) in the present invention, are explained.

Hereinafter, 9-azabicyclo[3.3.1]nonane N-oxyl represented by the following structural formula (E-1) is abbreviated as “ABNO”.

2-Azatricyclo[3.3.1.1 ^3,7 ]decane N-oxyl represented by the following structural formula (E-2) is abbreviated as “AZADO”.

2-Azatricyclo[3.3.1.0 ^5,8 ]nonane N-oxyl represented by the following structural formula (E-3) is abbreviated as “nor-AZADO”.

The numbers 1 to 10 in the following structural formulas (E-1) to (E-3) are the atomic position No. represents.

[Formula 25]

In the description of the substituent in formula (I), the numerical range written after “C” indicates the carbon number of the substituent. For example, “C1-12 alkyl group” means “an alkyl group having 1 to 12 carbon atoms.” .

R ^A in formulas (I) and (Ia) to (Ic) represents a substituent bonded to each carbon atom of a bicyclo ring structure or tricyclo ring structure, and is a substituent bonded to one or two carbon atoms of each carbon atom. . For example, the compound represented by formula (Ib) described later has the same meaning as the following formula (Ib'), and other formulas (I), (Ia), and (Ic) are also the same.

[Formula 26]

<Component (e-1)>

Component (e-1) is a compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group, and has a heterocyclic ring structure or heterotricyclic structure in which the carbon atom of the bicyclo ring structure or tricyclo ring structure is substituted with a nitroxyl radical group. It is a compound with a cyclo ring structure.

Component (e-1) is an isocyanate added to the ring-forming carbon atom of a compound having a heterobicyclo ring structure or heterotricyclo ring structure in which the carbon atom of the bicyclo ring structure or tricyclo ring structure is substituted with a nitroxyl radical group. It is a compound in which a group or an isocyanate-reactive functional group is bonded directly or through an arbitrary linking group.

Hereinafter, the structural portion other than the isocyanate group or isocyanate-reactive functional group of component (e-1) may be referred to as the “parent compound of component (e-1).” Components (e-3) and (e-4) described later are also referred to in the same way.

Examples of the parent compound of component (e-1) include the above-mentioned ABNO, AZADO, and nor-AZADO, but are not limited to these in any way. These ABNO, AZADO, and nor-AZADO may have a substituent other than an isocyanate group or an isocyanate-reactive functional group at any position. Substituents other than the isocyanate group or the isocyanate-reactive functional group include the substituent represented by R ^A in the formula (I) of component (e-2) described later, and are preferably a halogen atom or an alkyl group having 1 to 6 carbon atoms. , hydrogen atom, etc., and the substitution position is preferably at the 1, 3, 5, and 7 positions in the case of ABNO, AZADO, and nor-AZADO.

If two carbon atoms covalently bonded to the nitrogen atom of the nitroxyl radical group (hereinafter sometimes referred to as “adjacent carbon atoms”) are substituted with bulky substituents, the nitroxyl radical group suffers steric hindrance, There is a risk that the effects of the present invention may not be obtained. For this reason, when these adjacent carbon atoms have a substituent, it is preferable that there is only one substituent, and one is a hydrogen atom. The substituent substituted for these adjacent carbon atoms is preferably an alkyl group with 3 or less carbon atoms or a halogen atom.

Examples of the parent compound of component (e-1) include those shown below. In the following illustrative formula, “Ac” represents “acetyl group.”

[Formula 27]

There is no particular limitation on the position of substitution of the isocyanate group or isocyanate-reactive functional group with respect to the parent compound of component (e-1). In AZADO, positions 5 and 6 are preferred. In ABNO, positions 3 and 7 are preferred. In nor-AZADO, positions 3 and 7 are preferred.

When an isocyanate group or an isocyanate-reactive functional group is bonded to the parent compound of component (e-1) through an arbitrary linking group, the linking group may be an alkyl group having 1 to 6 carbon atoms, an arylene group such as a phenylene group, or a peptide bond. (-CO-NH-), urethane bond (-OCO-NH-), or a combination of two or more of these groups can be mentioned.

Component (e-1) is specifically 3-hydroxy-9-azabicyclo[3.3.1]nonane N-oxyl (3-HO-ABNO) represented by the structural formula (e-1-1) shown below. 5-hydroxy-2-azatricyclo[3.3.1.1 ^3,7 ]nonane N-oxyl (5-HO-AZADO) represented by structural formula (e-1-2), structural formula (e-1-3) ∼ A compound represented by (e-1-8) can be mentioned.

[Formula 28]

<Component (e-2)>

Component (e-2) is a compound represented by the following formula (I).

[Formula 29]

In formula (I), C ₁ and C ₂ represent carbon atoms. In formula ( _{I )} , ^{two R When R ​} _​ ^​ _​ ^​ _​

In formula (I), and R ^A in the linking group is hydrogen atom, halogen atom, C1-12 alkyl group, hydroxy group, hydroxy(C1-12 alkyl) group, amino group, amino(C1-12 alkyl) It represents a substituent selected from group, isocyanate group, and isocyanate (C1-12 alkyl) group. In addition, R ^A in formula (I) and in the above linking group is bonded to one or two carbon atoms of the bicyclo ring structure or tricyclo ring structure, respectively, and when the substituent is two or more, The substituents may be the same or different. A plurality of R ^A in formula (I) and the above linking group may be the same or different.

However, at least one of R ^A in formula (I) and the linking group is selected from a hydroxy group, a hydroxy (C1-12 alkyl) group, an amino group, an amino (C1-12 alkyl) group, and an isocyanate group. represents one or more substituents.

As component (e-2), compounds represented by any of the following formulas (Ia) to (Ic) are particularly preferable.

[Formula 30]

R ^A in formulas (Ia) to (Ic) has the same meaning as in formula (I).

Suitable examples and specific examples of component (e-2) include those exemplified by component (e-1).

<Ingredient (e-3)>

Component (e-3) is a compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group, and the nitroxyl radical group is not suffering from steric hindrance. Component (e-3) exhibits excellent effects as component (e) because the nitroxyl radical group is not subjected to steric hindrance.

Here, examples of structures in which the nitroxyl radical group is not subjected to steric hindrance include aspects such as the following (e-3-1) to (e-3-3).

(e-3-1): Two atoms covalently bonded to the nitrogen atom of the nitroxyl radical group (this atom is not limited to a carbon atom and may be a sulfur atom. Additionally, the two atoms may be the same or different Compounds in which the number of alkyl groups such as methyl groups covalently bonded to each of the above is 0 or 1.

(e-3-2): A compound in which among the two carbon atoms covalently bonded to the nitrogen atom of the nitroxyl radical group, at least one carbon atom is covalently bonded to one or more hydrogen atoms or halogen atoms.

(e-3-3): A compound in which both of the two carbon atoms covalently bonded to the nitrogen atom of the nitroxyl radical group are covalently bonded to one or more hydrogen atoms or halogen atoms.

In the above aspect (e-3-1), examples of the parent compound of component (e-3) include those exemplified below.

[Formula 31]

In the above aspect (e-3-2), examples of the parent compound of component (e-3) include those exemplified below.

[Formula 32]

In the above aspect (e-3-3), examples of the parent compound of component (e-3) include those exemplified below.

[Formula 33]

The substitution position of the isocyanate group or isocyanate-reactive functional group with respect to the compound parent of these components (e-3) and the suitable mode of the linking group of the isocyanate group or isocyanate-reactive functional group with the compound parent are the same as those for component (e-1). do.

<Ingredient (e-4)>

Component (e-4) is a compound in which an isocyanate group or an isocyanate reactive group is substituted for a compound parent having a nitroxy radical group, and the redox potential of the parent compound having a nitroxy radical group is 280 mV or less.

Compounds with a low redox potential tend to emit electrons and have a stable oxidation form, so they have excellent radical trapping performance and high reliability. If the compound parent compound has an oxidation-reduction potential below the above upper limit, the oxidation-reduction potential is low even if the compound is substituted with an isocyanate group or an isocyanate-reactive functional group directly or through a linking group, and exhibits an excellent effect as component (e).

Specifically, compounds having a nitroxyl radical group with an oxidation-reduction potential of 280 mV or less and their oxidation-reduction potential include the following.

It is preferable that component (e-4) uses such a compound as a base compound.

[Formula 34]

Conventional TEMPO has a high oxidation-reduction potential as follows. Therefore, TEMPOL has inferior radical trapping performance.

[Formula 35]

The substitution position of the isocyanate group or isocyanate-reactive functional group with respect to the compound parent of these components (e-4) and the suitable mode of the linking group of the isocyanate group or isocyanate-reactive functional group with the compound parent are the same as those for component (e-1). do.

The composition for a hologram recording medium of the present invention may contain, as component (e), only one of the components (e-1) to (e-4), or two or more of the components (e-1) to (e-4).

＜Component (f)＞

The composition for a hologram recording medium of the present invention preferably further contains as component (f) a curing catalyst that promotes the reaction between the compound having an isocyanate group of component (a) and the compound having an isocyanate reactive functional group of component (b). do. As the curing catalyst for component (f), it is preferable to use a bismuth-based catalyst that functions as a Lewis acid.

Examples of bismuth-based catalysts include tris(2-ethylhexanate)bismuth, tribenzoyloxybismuth, bismuth triacetate, tris(dimethyldiocarbamate)bismuth, bismuth hydroxide, triphenylbismuth (V) bis(trichloroarethate) ), tris(4-methylphenyl)oxobismuth (V), triphenylbis(3-chlorobenzoyloxy)bismuth (V), etc.

Among them, trivalent bismuth compounds are preferred in terms of catalytic activity, and are bismuth carboxylic acid, having the general formula Bi(OCOR) ₃ (R is a straight-chain, branched alkyl group, cycloalkyl group, or substituted or unsubstituted aromatic group). It is more preferable to indicate The bismuth-based catalyst may be used individually, or two or more types may be used together in any combination and ratio.

As a curing catalyst, another curing catalyst may be used together with the bismuth-based catalyst to adjust the reaction rate. There is no particular limitation on the catalyst that can be used in combination, as long as it does not conflict with the main spirit of the present invention. However, in order to obtain a synergistic effect of the catalyst, it is preferable to use a compound having an amino group in part of the structure. Examples include triethylamine (TEA), N,N-dimethylcyclohexylamine (DMEDA), N,N,N',N'-tetramethylethylenediamine (TMEDA), N,N,N',N' -Tetramethylpropane-1,3-diamine (TMPDA), N,N,N',N'-Tetramethylhexane-1,6-diamine (TMHMDA), N,N,N',N",N"- Pentamethyldiethylenetriamine (PMDETA), N,N,N',N",N"-pentamethyldipropylene-triamine (PMDPTA), triethylenediamine (TEDA), N,N'-dimethylpiperazine ( DMP), N,-methyl, N'-(2dimethylamino)-ethylpiperazine (TMNAEP), N-methylmorpholine (NMMO), N·(N',N'-dimethylaminoethyl)-morpholine ( Amine compounds such as DMAEMO), bis(2-dimethylaminoethyl) ether (BDMEE), ethylene glycol bis(3-dimethyl)-aminopropyl ether (TMEGDA), and diisopropylethylamine (DIEA) can be mentioned. Any one of these may be used individually, and two or more types may be used together in any combination and ratio.

＜Other ingredients＞

The composition for a hologram recording medium of the present invention may contain other components in addition to the components (a) to (f) described above, as long as they do not conflict with the main spirit of the present invention.

Other ingredients include solvents, plasticizers, dispersants, leveling agents, anti-foaming agents, adhesion promoters, etc. for preparing the recording layer of the hologram recording medium, chain transfer agents, polymerization terminators, compatibilizers, etc. for controlling the recording reaction. Reaction auxiliaries, sensitizers, antioxidants, etc. can be mentioned. These components may be used individually, or two or more types may be used together in any combination and ratio.

Among these, it is preferable to use a chain transfer agent. Among these, it is more preferable to use a compound having a terpenoid skeleton. The compound having a terpenoid skeleton may be any compound as long as it has a terpenoid skeleton. Specifically, monoterpenes (e.g., camphor, menthol, limonene, terpineol, geraniol, nerol, citronellol, terpinolene, α, β, γ-terpinene, etc.); Sesquiterpenes (for example, farnesol, nerolidol, caryophyllene, etc.); Diterpenes (for example, abietic acid, taxol, pimaric acid, geranylgeraniol, phytol, etc.); Triterpenes (for example, squalene, etc.); Carotenoids, etc. can be mentioned. Among these, terpinolene, α-terpinene, β-terpinene, γ-terpinene, etc. are particularly preferable. The compounds having the terpenoid skeleton of the above examples may be used individually, or two or more types may be used together in any combination and ratio.

<Composition ratio of each component in the composition for hologram recording medium>

The content of each component in the composition for a hologram recording medium of the present invention is arbitrary as long as it does not conflict with the main spirit of the present invention, but the content of each component is preferably within the following range.

The total content of component (a) and component (b) in the composition for hologram recording media of the present invention is usually 0.1% by weight or more, preferably 10% by weight or more, more preferably 35% by weight or more, and is usually 99.9% by weight. It is % by weight or less, preferably 99 % by weight or less, more preferably 98 % by weight or less. By setting this content to more than the above lower limit, it becomes easier to form a recording layer, and by setting it to less than the above upper limit, the content of other essential components can be secured.

The ratio of the number of isocyanate reactive functional groups of component (b) to the number of isocyanate groups of component (a) is preferably 0.1 or more, more preferably 0.5 or more, and usually 10.0 or less, preferably 2.0 or less. When this ratio falls within the above range, there are fewer unreacted functional groups and storage stability improves.

The content of component (c) in the composition for a hologram recording medium of the present invention is usually 0.1% by weight or more, preferably 1% by weight or more, more preferably 2% by weight or more, and is usually 80% by weight or less, preferably 50% by weight or less. It is % by weight or less, more preferably 30 % by weight or less. Sufficient diffraction efficiency is obtained when the amount of component (c) is more than the above lower limit, and compatibility of the recording layer is maintained when the amount is less than the above upper limit.

The content of component (d) in the composition for hologram recording media of the present invention is usually 0.1% by weight or more, preferably 0.2% by weight or more, more preferably 0.3% by weight or more, with respect to the content of component (c), usually 20% by weight. It is % by weight or less, preferably 18 % by weight or less, more preferably 16 % by weight or less. When the ratio of component (d) is more than the above lower limit, sufficient recording sensitivity can be obtained, and when the ratio is less than the above upper limit, sensitivity reduction resulting from a bimolecular stopping reaction due to excessive radical generation can be suppressed.

The content of component (e) in the composition for a hologram recording medium of the present invention is such that the molar ratio of component (e) and component (d) (component (e)/component (d)) is usually 0.1 or more, especially 0.2 or more, especially 0.3. It is preferably 10 or less, especially 8 or less, and especially 6 or less.

If component (e)/component (d) is more than the above lower limit, the effect of improving M/# by containing component (e) can be effectively obtained, and if it is less than the above upper limit, radical polymerization occurs during exposure for recording purposes. By proceeding with the reaction, the degree of refractive index modulation necessary for forming a diffraction grating can be obtained, and sufficient recording sensitivity can be obtained.

The content of component (f) in the composition for hologram recording media of the present invention is preferably determined in consideration of the reaction rates of component (a) and component (b), and is usually 5% by weight or less, preferably 4% by weight or less. , more preferably 1% by weight or less, and preferably 0.001% by weight or more.

The total amount of other components other than components (a) to (f) in the composition for hologram recording media of the present invention may be 30% by weight or less, preferably 15% by weight or less, and more preferably 5% by weight or less. .

<Method for producing composition for hologram recording medium>

When producing the composition for a hologram recording medium of the present invention, components (a) to (e), preferably components (a) to (f), may be mixed in any combination and order, and other components may be mixed at the same time. You may mix by combining.

The composition for a hologram recording medium of the present invention can be produced, for example, by the following method, but the present invention is not limited to this.

Mix all ingredients except component (b) and component (f) to make solution A. A mixture of component (b) and component (f) is called solution B. It is desirable to dehydrate and degas each liquid. If dehydration and deaeration are not performed, or if dehydration and deaeration are insufficient, bubbles may be generated during media production, and a uniform recording layer may not be obtained. During this dehydration and deaeration, heating and pressure reduction may be performed as long as each component is not damaged.

Regarding component (e), since it is a small component, it is preferable to prepare a masterbatch in advance in order to improve uniform dispersibility in the composition and ensure chemical bonding with component (a) and component (b). . For example, when component (e) has an isocyanate reactive group, a master batch is prepared by mixing a portion of component (a), for example, 10 to 90% by weight, with component (e), and then mixed with component (b) and component (b). Liquid A, which is a mixture of all components other than (e) and component (f) (the remainder of the masterbatch for component (a)), is mixed with liquid B, which is a mixture of component (b) and component (f). desirable. In addition, when component (e) has an isocyanate group, a masterbatch in which component (b) and component (e) are mixed in advance may be prepared in the same manner.

When component (e) has an isocyanate-reactive functional group, a portion of component (f), for example, 10 to 90% by weight, is further mixed with the master batch of component (e), and liquid B is mixed with component (f). You may mix the remainder.

Mixing of liquid A and liquid B, or mixing liquid A, liquid B, and the masterbatch of component (e) is performed immediately before molding. At this time, it is also possible to use mixing technology according to the conventional method. When mixing liquid A and liquid B, or mixing liquid A, liquid B, and the masterbatch of component (e), degassing may be performed as necessary to remove residual gas. In addition, it is preferable that liquid A and liquid B, or the master batch of component (e), be subjected to a filtration process individually or after mixing to remove foreign substances and impurities, and it is more preferable to filter each liquid separately. . As component (a)', an isocyanate functional prepolymer obtained by reaction of excess component (a) and component (b) may be used. Additionally, as component (b)', an isocyanate-reactive prepolymer obtained by reaction of excess component (b) and component (a) may be used.

[Cured material for hologram recording media]

By curing the composition for a hologram recording medium of the present invention, the cured product for a hologram recording medium of the present invention can be obtained.

There is no particular limitation on the method for producing the cured product for a hologram recording medium of the present invention, and when producing the composition for a hologram recording medium of the present invention, the above-mentioned liquid A and B or liquid A and B and component (e) By mixing the master batch, it can be cured into a cured product for a hologram recording medium.

At this time, in order to promote the curing reaction, heating may be performed at 30 to 100°C for approximately 1 to 72 hours.

The cured product for a hologram recording medium of the present invention can also be manufactured according to the recording layer formation method in the manufacturing method of the hologram recording medium of the present invention described later.

The cured product for a hologram recording medium of the present invention obtained by curing the composition for a hologram recording medium of the present invention is formed of component (a) and component (b) for the same reason as the composition for hologram recording medium of the present invention. The total content of the PG unit and TMG unit derived from component (b) in the matrix is preferably 30% by weight or less, more preferably 27% by weight or less, especially preferably 25% by weight or less, and the PG unit and the TMG unit are It is best not to include it.

In addition, the cured product for a hologram recording medium of the present invention has a CL unit content derived from component (b) in the matrix formed from component (a) and component (b) of 20% by weight or more, especially 25% by weight or more, In particular, it is preferably 30 to 70% by weight.

The content of the PG unit, TMG unit, and CL unit derived from component (b) in the cured material for a hologram recording medium of the present invention can be determined by, for example, alkaline hydrolysis of the cured material for a hologram recording medium, and the polyol component obtained. It can be analyzed and quantified by nuclear magnetic resonance (NMR) or gas chromatography mass spectrometry (GC/MS).

The presence of a compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group of component (e) in the cured product for a hologram recording medium of the present invention can be confirmed by electron spin resonance (ESR).

[Laminate for hologram recording media]

A laminate for a hologram recording medium can be obtained by laminating the cured product for a hologram recording medium of the present invention with a support as a recording layer. The support may be formed on one side or both sides of the recording layer made of cured material for hologram recording media.

Details of the recording layer and support will be described later.

The method of forming the recording layer made of the cured material for a hologram recording medium on the support is the same as the method of manufacturing the hologram recording medium of the present invention.

[Hologram recording medium]

By subjecting the composition for a hologram recording medium of the present invention to interference exposure, the hologram recording medium of the present invention can be obtained.

Below, preferred embodiments of the hologram recording medium of the present invention will be described.

The hologram recording medium of the present invention includes a recording layer and, if necessary, an additional support or other layers. Typically, a hologram recording medium has a support, and a recording layer or other layers are laminated on this support to form a hologram recording medium. However, if the recording layer or other layers have the strength or durability required for the medium, the hologram recording medium does not need to have a support. Examples of other layers include a protective layer, a reflective layer, and an anti-reflective layer (anti-reflective film).

The recording layer of the hologram recording medium of the present invention is preferably formed of the composition for the hologram recording medium of the present invention.

＜Recording layer＞

The recording layer of the hologram recording medium of the present invention is a layer formed by the composition for a hologram recording medium of the present invention, and is a layer in which information is recorded. Information is usually recorded as a hologram. As will be described in detail in the recording method section described later, a portion of the polymerizable monomer contained in the recording layer undergoes chemical changes such as polymerization during hologram recording. Therefore, in the hologram recording medium after recording, a part of the polymerizable monomer is consumed and exists as a compound after reaction, such as a polymer.

There is no particular limitation on the thickness of the recording layer, and it may be determined appropriately considering the recording method, etc., but in general, it is usually 1 μm or more, preferably 10 μm or more, and usually 3000 μm or less, preferably 2000 μm or less. . By setting the thickness of the recording layer to the above lower limit or more, the selectivity of each hologram can be increased during multiple recording on a hologram recording medium, and the degree of multiple recording can be increased. By keeping the thickness of the recording layer below the above upper limit, it becomes possible to mold the entire recording layer uniformly, and multiple recording with uniform diffraction efficiency of each hologram and a high S/N ratio can be performed.

It is preferable that the shrinkage rate of the recording layer due to exposure during recording and reproduction of information is 0.5% or less.

＜Support＞

There is no particular limitation on the details of the support, and any support can be used as long as it has the strength and durability required for the medium.

There are no restrictions on the shape of the support, but it is usually formed in a flat or film shape.

There are no restrictions on the material constituting the support, and it may be transparent or opaque.

Examples of transparent materials for the support include organic materials such as acrylic, polyethylene terephthalate, polyethylene naphthoate, polycarbonate, polyethylene, polypropylene, amorphous polyolefin, polystyrene, and cellulose acetate; Examples include inorganic materials such as glass, silicon, and quartz. Among these, polycarbonate, acrylic, polyester, amorphous polyolefin, glass, etc. are preferable, and in particular, polycarbonate, acrylic, amorphous polyolefin, and glass are more preferable.

On the other hand, examples of opaque materials for the support include metals such as aluminum; Examples include coating the transparent support with a metal such as gold, silver, or aluminum, or a dielectric such as magnesium fluoride or zirconium oxide.

There is no particular limitation on the thickness of the support, but it is usually preferably within the range of 0.05 mm or more and 1 mm or less. If the thickness of the support is more than the above lower limit, the mechanical strength of the hologram recording medium can be obtained and bending of the substrate can be prevented. If the thickness of the support is below the above upper limit, the amount of light transmitted is maintained, and an increase in cost can be suppressed.

Surface treatment may be performed on the surface of the support. This surface treatment is usually performed to improve the adhesion between the support and the recording layer. Examples of surface treatment include corona discharge treatment on the support or forming an undercoat layer on the support in advance. Compositions of the undercoat layer include halogenated phenols, partially hydrolyzed vinyl chloride-vinyl acetate copolymers, and polyurethane resins.

The surface treatment of the support may be performed for purposes other than improving adhesiveness. Examples include, for example, a reflective coat treatment to form a reflective coat layer made of metal such as gold, silver, or aluminum; Examples include dielectric coat treatment to form a dielectric layer such as magnesium fluoride or zirconium oxide. These layers may be formed in a single layer or in two or more layers.

Surface treatment of the support may be performed for the purpose of controlling the gas and moisture permeability of the substrate. For example, the reliability of the medium can be further improved by giving the support between the recording layer a function of suppressing gas or moisture permeability.

The support may be formed only on either the upper or lower side of the recording layer of the hologram recording medium of the present invention, or may be formed on both sides. However, when a support is formed on both the upper and lower sides of the recording layer, at least one side of the support is made transparent to transmit active energy rays (excitation light, reference light, reproduction light, etc.).

In the case of a hologram recording medium having a support on one or both sides of the recording layer, a transmissive or reflective hologram can be recorded. When a support having reflective properties is used on one side of the recording layer, a reflective hologram can be recorded.

Patterning for data addresses may be formed on the support. There is no limitation to the patterning method in this case, but for example, unevenness may be formed on the support itself, a pattern may be formed on the reflective layer described later, or it may be formed by a method combining these.

＜Protective layer＞

The protective layer is a layer to prevent the effects of oxygen or moisture on the recording layer, such as a decrease in sensitivity or deterioration of storage stability. There is no limitation on the specific composition of the protective layer, and it is possible to arbitrarily apply a known one. For example, a layer made of water-soluble polymer, organic/inorganic material, etc. can be formed as a protective layer.

The formation position of the protective layer is not particularly limited. For example, it may be formed on the surface of the recording layer, between the recording layer and the support, or may be formed on the outer surface of the support. The protective layer may be formed between the support and other layers.

＜Reflective layer＞

The reflective layer is formed when the hologram recording medium is configured to be reflective. In the case of a reflective hologram recording medium, the reflective layer may be formed between the support and the recording layer, or may be formed on the outer surface of the support, but it is usually preferable to be between the support and the recording layer.

As the reflective layer, any known material can be used, for example, a thin film of metal can be used.

＜Anti-reflective film＞

For both transmissive and reflective hologram recording media, an anti-reflection film may be formed on the side where the object light and the read output light enter and exit, or between the recording layer and the support. The anti-reflection film improves the efficiency of light use and also functions to suppress the generation of ghost images.

As the anti-reflection film, any known one can be used.

＜Manufacturing method of hologram recording medium＞

There are no restrictions on the manufacturing method of the hologram recording medium of the present invention. For example, it can be manufactured by applying the composition for a hologram recording medium of the present invention on a support using a non-solvent and forming a recording layer. Any method can be used as the application method. Specific examples include spray method, spin coat method, wire bar method, dip method, air knife coat method, roll coat method, blade coat method, and doctor roll coat method.

In particular, when forming a recording layer with a thick film, a method of putting the composition for a hologram recording medium of the present invention into a mold and molding it, or a method of coating it on a release film and punching out the mold can also be used.

It may be prepared by mixing the composition for a hologram recording medium of the present invention with a solvent or additive to prepare a coating solution, and applying this onto a support and drying it to form a recording layer. In this case as well, any method can be used as the application method, for example, the same method as described above can be adopted.

There are no restrictions on the solvent used in the coating liquid, but it is usually preferable to use a solvent that has sufficient solubility for the components used, provides good coating properties, and does not invade supports such as resin substrates. Examples of solvents include ketone-based solvents such as acetone and methyl ethyl ketone; Aromatic solvents such as toluene and xylene; Alcohol-based solvents such as methanol and ethanol; Ketone alcohol-based solvents such as diacetone alcohol; Ether-based solvents such as tetrahydrofuran; Halogen-based solvents such as dichloromethane and chloroform; Cellosolve-based solvents such as methyl cellosolve and ethyl cellosolve; Propylene glycol-based solvents such as propylene glycol monomethyl ether and propylene glycol monoethyl ether; Ester solvents such as ethyl acetate and methyl 3-methoxypropionate; Perfluoroalkyl alcohol-based solvents such as tetrafluoropropanol; Highly polar solvents such as dimethylformamide and dimethyl sulfoxide; Chain hydrocarbon-based solvents such as n-hexane; Cyclic hydrocarbon-based solvents such as cyclohexane and cyclooctane; Or a mixed solvent thereof, etc. can be mentioned.

Solvents may be used individually, or two or more types may be used together in any combination and ratio.

There is no limit to the amount of solvent used. However, from the viewpoint of coating efficiency and handleability, it is preferable to prepare a coating liquid with a solid content concentration of about 1 to 1000% by weight.

When the resin matrix consisting of components (a) and (b) of the composition for a hologram recording medium of the present invention is thermoplastic, the composition for a hologram recording medium of the present invention can be manufactured by, for example, injection molding, sheet molding, hot pressing, etc. The recording layer can be formed by molding.

When the resin matrix consisting of components (a) and (b) is light or thermosetting with few volatile components, the recording layer is formed by molding the composition for a hologram recording medium of the present invention by, for example, a reaction injection molding method or a liquid injection molding method. can be formed. In this case, if the molded body has sufficient thickness, rigidity, strength, etc., the molded body can be used as a hologram recording medium.

Methods for producing a hologram recording medium include, for example, a method of applying a composition for a hologram recording medium melted by heat to a support, cooling and solidifying to form a recording layer, and a method of manufacturing a liquid hologram recording medium composition on a support. A method of producing a recording layer by coating and curing by thermal polymerization, and a method of forming a recording layer by applying a liquid composition for hologram recording media to a support and curing it by photopolymerization, can also be mentioned.

The hologram recording medium produced in this way can take the form of a free-standing slab or disk, and can be used in three-dimensional image display devices, diffractive optical elements, and large-capacity memories, among other things.

In particular, the hologram recording medium of the present invention using the composition for a hologram recording medium of the present invention has a high M/# and suppressed coloring, and is useful as an AR glass light guide plate.

＜Large capacity memory usage＞

Both writing (recording) and reading output (playback) of information to the hologram recording medium of the present invention are performed by irradiation of light.

When recording information, light capable of causing chemical changes in polymerizable monomers, that is, polymerization and concentration changes, is used as object light (also called recording light).

For example, when recording information as a volume hologram, object light is irradiated to the recording layer together with reference light, and the object light and reference light are allowed to interfere in the recording layer. As a result, the interference light causes polymerization and concentration change of the polymerizable monomer in the recording layer, and as a result, the interference pattern generates a refractive index difference in the recording layer, and the interference pattern recorded in the recording layer causes It is recorded as a hologram.

When reproducing a volume hologram recorded on a recording layer, a predetermined reproduction light (usually a reference light) is irradiated to the recording layer. The irradiated reproduction light generates diffraction according to the interference pattern. Since this diffracted light contains the same information as the recording layer, the information recorded in the recording layer can be reproduced by reading the diffracted light using an appropriate detection means.

The wavelength ranges of object light, reproduction light, and reference light are arbitrary depending on each application, and may be the visible light range or the ultraviolet range. Preferred examples of these lights include solid lasers such as ruby, glass, Nd-YAG, and Nd-YVO ₄ ; Diode lasers such as GaAs, InGaAs, and GaN; Gas lasers such as helium-neon, argon, krypton, excimer, and CO ₂ ; Lasers with excellent monochromaticity and directivity, such as dye-containing die lasers, can be mentioned.

There are no restrictions on the irradiation amounts of object light, reproduction light, and reference light, and the irradiation amount is arbitrary as long as it is within the range where recording and reproduction are possible. If the irradiation amount is extremely small, the chemical change in the polymerizable monomer may be too incomplete and the heat resistance and mechanical properties of the recording layer may not be sufficiently expressed. Conversely, if the irradiation amount is extremely large, the components of the recording layer (holographic recording of the present invention) may not be sufficiently developed. components of the composition for media) may cause deterioration. Therefore, the object light, reproduction light, and reference light are usually 0.1 J/cm2 or more, 20 J/cm2 or more, depending on the composition of the composition for a hologram recording medium of the present invention used to form the recording layer, the type and mixing amount of the photopolymerization initiator, etc. Investigate in a range of ㎠ or less.

Hologram recording methods include a polarization collinear hologram recording method and a reference light incident angle multiple type hologram recording method. When using the hologram recording medium of the present invention as a recording medium, it is possible to provide good recording quality using any recording method.

The hologram recording medium of the present invention has the characteristics of high M/# and light transmittance and small change in chromaticity.

The refractive index modulation caused by holographic recording is measured as diffraction efficiency. Holographic records can be recorded multiple times. Multiplexing methods include angle multiplexing performed by changing the incident angle of intersecting light at a fixed angle, shift multiplexing performed by moving the location without changing the incident angle, and wavelength multiplexing performed by changing the wavelength. However, angle multiplexing is easy, and this allows you to understand the performance of the material or each component.

Since M/#, which is the sum of the square root of the diffraction efficiency over all multiples, is a value that serves as a standard for recording capacity, it can be said that the larger it is, the better the performance as a medium. In general, the higher the polymerizable monomer content, the greater the diffraction efficiency and the greater M/#.

The M/# of the recording layer of the hologram recording medium of the present invention is 20 or more, preferably 30 or more, and more preferably 35 or more when evaluated as a 500 μm thick recording layer. In addition, as described above, the larger the value of M/#, the more desirable it is, and the upper limit can be changed depending on the required recording capacity.

This M/# is measured by the method shown in the Examples described later.

In addition, layers other than the recording layer that constitutes the hologram recording medium, such as the substrate, protective layer, and reflection layer, do not significantly affect the value of M/#, so even for media with different layer compositions other than the recording layer, M/# ＃ Direct comparison of is possible.

Light transmittance in the hologram recording medium of the present invention is an important indicator. Since the transmittance before recording is based on the reflectance of the substrate-air interface and the absorption of the unreacted initiator in the recording medium, it is calculated from the reflectance of the substrate-air interface, the molar extinction coefficient and concentration of the initiator in the hologram recording medium, and the thickness of the hologram recording medium. It can be calculated. The light transmittance calculated by calculation is called the design transmittance.

The design transmittance of the holographic recording medium is calculated by the following equation from the reflectance of the substrate-air interface, the molar extinction coefficient of the photo polymerization initiator in the holographic recording medium, the concentration of the photo polymerization initiator in the holographic recording medium, and the thickness of the holographic recording medium. .

T = R ² × 10 ^(-ε×c×d)

Here, T is the design transmittance, R is the reflectance at the interface between the substrate and air, ε is the molar extinction coefficient of the photo polymerization initiator, c is the concentration of the polymerization initiator in the hologram recording medium, and d is the thickness of the hologram recording medium.

If the measured transmittance before recording is lower than the design transmittance, it suggests that the hologram recording medium is colored due to another factor. Coloration of the hologram recording medium leads to a decrease in image quality when used as a light guide plate for AR glasses. Therefore, the smaller the difference between the design transmittance and the transmittance before recording, the better the performance of the hologram recording medium.

The light used to measure this light transmittance is preferably at or near the recording wavelength. However, before recording, the chemical change of the photopolymerization initiator in the recording layer constituting the hologram recording medium becomes significant, so the transmittance changes with time. Therefore, the light transmittance before recording needs to be measured for a sufficiently short time (approximately 1 second) to obtain reliable and reproducible measured values. On the other hand, after recording, the photopolymerization initiator is consumed and no temporal change occurs, so there is no need to worry about the measurement time of the light transmittance.

In general, it is desirable for the design transmittance and the transmittance before recording to be identical, but if there is a difference between the two, the difference is preferably within approximately 3%, more preferably within 2%, and still more preferably within 1%. . In the hologram recording medium of the present invention, when evaluated with a film thickness of 500 μm of the recording layer, the transmittance before recording is within the above range and can usually achieve 3% or less, preferably 1% or less. In addition, this light transmittance is specifically measured by the method shown in the Examples described later.

＜Use of AR glass light guide plate＞

With respect to the hologram recording medium of the present invention, a volume hologram is recorded in the same manner as the above-described large-capacity memory application.

For the volume hologram recorded on the recording layer, a predetermined reproduction light is irradiated onto the recording layer. The irradiated reproduction light generates diffraction according to the interference pattern. At this time, even if the wavelength of the reproduction light does not match the wavelength of the recording light, if the interference pattern and Bragg condition are established, diffraction occurs. Therefore, by recording the corresponding interference pattern according to the wavelength and angle of incidence of the reproduction light to be diffracted, diffraction can be generated for reproduction light in a wide wavelength range, thereby expanding the display color gamut of AR glasses.

Depending on the wavelength and diffraction angle of the playback light, if the corresponding interference pattern is recorded, the playback light incident from the outside of the hologram recording medium is guided inside the hologram recording medium, or the playback light that has been guided inside the hologram recording medium is reflected. By dividing, enlarging, or reducing the reproduction light that has been guided inside the hologram recording medium, it can be emitted to the outside of the hologram recording medium, thereby widening the viewing angle of the AR glasses.

The wavelength range of object light and reproduction light is arbitrary depending on each application, and may be the visible light range or the ultraviolet range. Preferred ones among these lights include the laser and the like described above. The reproduction light is not limited to a laser or the like, and display devices such as a liquid crystal display (LCD) and an organic electroluminescence display (OLED) are also mentioned as preferred ones.

There are no restrictions on the irradiation amounts of object light, reproduction light, and reference light, and the irradiation amount is arbitrary as long as it is within the range where recording and reproduction are possible. If the irradiation amount is extremely small, the chemical change in the polymerizable monomer may be too incomplete and the heat resistance and mechanical properties of the recording layer may not be sufficiently expressed. Conversely, if the irradiation amount is extremely large, the components of the recording layer (holographic recording of the present invention) may not be sufficiently developed. components of the composition for media) may cause deterioration. Therefore, the object light, reproduction light, and reference light are usually 0.1 J/cm2 or more, 20 J/cm2 or more, depending on the composition of the composition for a hologram recording medium of the present invention used to form the recording layer, the type and mixing amount of the photopolymerization initiator, etc. Investigate in a range of ㎠ or less.

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples as long as it does not deviate from the gist of the present invention.

[Raw materials used]

The composition raw materials used in the examples and comparative examples are as follows.

Component (a): Compound having an isocyanate group

・Duranate (registered trademark) TSS-100: hexamethylene diisocyanate-based polyisocyanate (NCO 17.6%) (manufactured by Asahi Chemical Company)

Component (b): Compound having an isocyanate reactive functional group

· Fraxel PCL-205U: polycaprolactone diol (molecular weight 530) (manufactured by Daicel)

· Fraxel PCL-305: Polycaprolactone triol (molecular weight 550) (manufactured by Daicel)

Component (c): Polymerizable monomer

·HLM101: 2,2-bis(4-dibenzothiophenylthiomethyl)-3-(4-dibenzothiophenylthio)propylacrylate

·BDTPA: 2,4-bis(4-dibenzothiophenyl)-1-phenylacrylate

Component (d): Photopolymerization initiator

HLI02: 1-(9-ethyl-6-cyclohexanoyl-9H-carbazol-3-yl)-1-(O-acetyloxime)methyl glutarate

Component (e): A compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group.

·3-HO-ABNO: 3-hydroxy-9-azabicyclo[3.3.1]nonane N-oxyl

·5-HO-AZADO: 5-hydroxy-2-azatricyclo[3.3.1.1 ^3,7 ]decane N-oxyl

Component (f): Curing catalyst

· Octylic acid solution of tris(2-ethylhexanoate)bismuth (active ingredient amount 56% by weight)

Ingredient (g): Others

·Methyl linoleate (LM): manufactured by Tokyo Chemical Industry Co., Ltd.

·TEMPOL: 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (manufactured by Tokyo Kasei Corporation)

Methyl linoleate was used as a replacement for component (e) in Comparative Example 1.

TEMPOL was used as a replacement for component (e) in Comparative Examples 2 to 9.

Hereinafter, component (e) and component (g) may be referred to as “additives.”

[Example 1]

＜Preparation of 3-HO-ABNO masterbatch＞

Duranate (TM) TSS-100: 0.15 g of 3-HO-ABNO: 2.85 g was dissolved. A solution of tris(2-ethylhexanoate)bismuth in octylic acid (0.002 g) was dissolved therein, stirred at 45°C under reduced pressure, and allowed to react for 2 hours. The reaction of the hydroxyl group of 3-HO-ABNO to the isocyanate group was confirmed by observing the disappearance of the peak at 3450 cm ^-1 derived from the hydroxyl group of 3-HO-ABNO in FT-IR. Additionally, Duranate (TM) TSS-100: 12 g was added and mixed to prepare a 3-HO-ABNO masterbatch.

<Preparation of composition for hologram recording medium>

Polymerizable monomer HLM101: 0.362 g and photopolymerization initiator HLI02: 0.0145 g were dissolved in 3.69 g of Duranate (TM) TSS-100 to prepare solution A.

Separately, Fraxel PCL-205U (polycaprolactone diol (molecular weight 530)): 2.42 g and Fraxel PCL-305 (polycaprolactone triol (molecular weight 550)): 1.04 g were mixed (Fraxel PCL-205U: Fraxel PCL- 305 = 70:30 (weight ratio)), tris(2-ethylhexanoate)bismuth octylic acid solution: 0.0003 g was dissolved to make solution B.

After degassing Liquid A and Liquid B at 45°C for 2 hours under reduced pressure, Liquid A: 2.36 g, Liquid B: 2.35 g, and 3-HO-ABNO masterbatch: 0.285 g were stirred and mixed, and kept for several minutes. Degassed in vacuum.

Subsequently, the vacuum-degassed liquid mixture was poured onto a slide glass on which a spacer sheet with a thickness of 0.5 mm was placed on two opposing short sides, the slide glass was placed on top, and the surrounding area was secured with a clip to form 80 A sample for evaluating a composition for a hologram recording medium was prepared by heating at ℃ for 24 hours. In this sample for evaluation, a recording layer with a thickness of 0.5 mm was formed between a glass slide as a cover.

This composition for a hologram recording medium contains 4.6% by weight of the polymerizable monomer of component (c), and the photopolymerization initiator of component (d) is 4% by weight, 3-HO-, based on the polymerizable monomer of component (c). The molar ratio of ABNO and the photopolymerization initiator of component (d) was 1, and the ratio of the hydroxyl group of component (b) to the isocyanate group of component (a) (OH/NCO) was 1.0.

[Examples 2 to 4]

A composition for a hologram recording medium was prepared in the same manner as in Example 1, except that the 3-HO-ABNO masterbatch was mixed so that the molar ratio of 3-HO-ABNO and the photopolymerization initiator of component (d) was the value shown in Table 1. Samples for evaluating compositions for holographic recording media were produced.

[Examples 5 to 8]

5-HO-AZADO is used instead of 3-HO-ABNO, and the 5-HO-AZADO masterbatch is prepared so that the molar ratio of 5-HO-AZADO and the photopolymerization initiator of component (d) is the value shown in Table 1. A composition for a hologram recording medium and a sample for evaluating the composition for a hologram recording medium were prepared in the same manner as in Example 1 except for mixing.

[Examples 9 to 10]

BDTPA is used instead of HLM101, and the mixing ratio of Fraxel PCL-205U and Fraxel PCL-305 is Fraxel PCL-205U: Fraxel PCL-305 = 90:10 (weight ratio), and the mixing amount and molar ratio of each component are shown in the table. A composition for a hologram recording medium and a sample for evaluating the composition for a hologram recording medium were prepared in the same manner as in Example 5, except that the mixture was mixed to obtain the values shown in 1.

[Comparative Example 1]

<Preparation of composition for hologram recording medium>

In Duranate (TM) TSS-100: 4.04 g, polymerizable monomer HLM101: 0.386 g, photopolymerization initiator HLI02: 0.0154 g, and methyl linoleate: 3.78 mg were dissolved to prepare solution A.

Separately, Fraxel PCL-205U (polycaprolactone diol (molecular weight 530)): 2.25 g and Fraxel PCL-305 (polycaprolactone triol (molecular weight 550)): 0.964 g were mixed, and tris (2-ethylhexanoate) ) Octylic acid solution of bismuth: 0.0003 g was dissolved to make solution B.

After degassing Liquid A and Liquid B at 45°C for 2 hours under reduced pressure, 2.65 g of Liquid A and 2.35 g of Liquid B were stirred and mixed, and further degassed in vacuum for several minutes.

Subsequently, the vacuum-degassed liquid mixture was poured onto a glass slide on which a spacer sheet with a thickness of 0.5 mm was placed on the two opposite sides, the slide glass was placed on top, the glass slide was secured around it with a clip, and the mixture was heated at 80°C for 24 hours. A sample for evaluating a composition for a holographic recording medium was produced. In this sample for evaluation, a recording layer with a thickness of 0.5 mm was formed between a glass slide as a cover.

This composition for a hologram recording medium contains 4.6% by weight of the polymerizable monomer of component (c), 4% by weight of the photopolymerization initiator of component (d) relative to the polymerizable monomer of component (c), and a photopolymerization of methyl linoleate. The molar ratio of the polymerization initiator contained was 0.42.

[Comparative Examples 2 to 6]

In Example 1, TEMPOL was used instead of 3-HO-ABNO, and the TEMPOL masterbatch was blended so that the molar ratio of TEMPOL and the photopolymerization initiator of component (d) was the value shown in Table 2. In the same manner as in 1, a composition for a hologram recording medium and a sample for evaluating the composition for a hologram recording medium were produced.

[Comparative Examples 7 to 9]

BDTPA is used instead of HLM101, and the mixing ratio of Fraxel PCL-205U and Fraxel PCL-305 is Fraxel PCL-205U: Fraxel PCL-305 = 90:10 (weight ratio), and the mixing amount and molar ratio of each component are shown in the table. A composition for a hologram recording medium and a sample for evaluating the composition for a hologram recording medium were prepared in the same manner as in Comparative Example 2, except that the composition was mixed to obtain the values shown in 2.

[Hologram recording and evaluation method]

Using samples for evaluation of compositions for hologram recording media produced in Examples and Comparative Examples, hologram recording and hologram recording performance of the hologram recording medium were evaluated in the order described below.

Hologram recording was performed using a semiconductor laser with a wavelength of 405 nm, an exposure power density of 7.5 mW/cm2 per beam, and an exposure apparatus shown in FIG. 1 to record a two-bundle plane wave.

61 multiple recordings were made on the medium from -18° to 18° at the same point at 0.6° intervals, and the sum of the square roots of the diffraction efficiencies at that time was taken as M/# (M number).

This is explained in detail below.

(hologram recording)

1 is a configuration diagram showing the outline of a device used for hologram recording.

In Fig. 1, S is a sample of a hologram recording medium, and M1 to M3 all represent mirrors. PBS represents a polarizing beam splitter, and L1 represents a laser light source for recording light that emits light with a wavelength of 405 nm (a single-mode laser manufactured by TOPTICA Photonics that produces light around 405 nm in wavelength (“L1” in FIG. 1)). L2 represents a laser light source for reproduction light that emits light with a wavelength of 633 nm. PD1, PD2, and PD3 represent photodetectors. 1 represents the LED unit.

As shown in FIG. 1, light with a wavelength of 405 nm was split by a polarizing beam splitter (“PBS” in the figure), and the two beams intersected on the recording surface so that the angle formed was 37.3°. At this time, the bisector of the angle formed by the two beams is perpendicular to the recording surface, and the vibration plane of the electric field vector of the two beams obtained by division is perpendicular to the plane containing the two intersecting beams. and investigated.

After recording the hologram, using a He-Ne laser capable of obtaining light with a wavelength of 633 nm (V05-LHP151 manufactured by Meles Griot: “L2” in the drawing), the light is transmitted at an angle of 30.0° with respect to the recording surface. irradiation, and detecting the diffracted light using a photodiode and a photosensor amplifier (S2281, C9329 manufactured by Hamamatsu Photonics Co., Ltd.: "PD1" in the drawing) to determine whether hologram recording is being performed correctly. The diffraction efficiency of a hologram is given as the ratio of the intensity of the diffracted light to the sum of the intensity of the transmitted light and the intensity of the diffracted light.

(Measurement of M/#)

The angle at which the sample is moved relative to the optical axis (the angle formed by the normal line from the sample and the bisector of the internal angle at the point where the incident light from the two light bundles, i.e., the incident light from mirrors M1 and M2 in Figure 1 intersect) ranges from -18° to 18°. 61 multiple recordings were made at 0.6 degree intervals.

61 After multiple recording, the remaining initiator and monomer were consumed by turning on the LED unit (Figure 1, center wavelength 405 nm) for a certain period of time. This process is called post-exposure. The power of the LED was set to 50 mW/cm2 and the integrated energy was irradiated to 3 J/cm2.

Subsequently, light (wavelength 405 nm) from mirror M1 in FIG. 1 was irradiated, and diffraction efficiency was measured from an angle of -19° to 19°. The sum of the square roots of the obtained diffraction efficiencies over the entire multiple recordings was taken as M/#.

Using multiple prepared optical recording media, evaluation was performed multiple times while changing the irradiation energy conditions, such as an increase/decrease in the irradiation energy at the beginning of recording and an increase/decrease in the total irradiation energy, while maintaining a diffraction efficiency of several percent or more for each recording. Conditions were sought where almost all of the contained monomers were consumed up to 61 multiple recordings (M/# reached almost equilibrium by 61 multiple recordings), and the maximum value as M/# was obtained. And the obtained maximum value was taken as M/# of the medium.

(Calculation of sensitivity)

The sensitivity was defined as the value obtained by multiplying the above-mentioned M/# by 0.8 and dividing it by the energy irradiated until the above-described M/# reached 80%.

(Measurement of transmittance before recording and transmittance after recording)

The transmittance before recording was measured by measuring the ratio of transmitted light power to incident light power of the evaluation sample before recording.

After hologram recording, the post-recording transmittance was measured by measuring the ratio of transmitted light power to incident light power of the post-exposed evaluation sample.

The results of evaluating the hologram recording media produced in Examples 1 to 10 and Comparative Examples 1 to 9 by the above method are shown in Tables 1 and 2 below.

The relationship between M/# and the amount of additive added (additive/component (d) molar ratio) is shown in Figure 2.

In Tables 1 and 2, the value in parentheses in the column of component (b) represents the ratio (% by weight) of Fraxel PCL-205U to the total of Fraxel PCL-205U and Fraxel PCL-305.

The numerical value in parentheses in the column for component (c) represents the content (% by weight) of component (c) in the composition for hologram recording media.

The numerical value in parentheses in the column of component (d) represents the “component (d)/component (c)” weight ratio in the composition for hologram recording media.

“Component (a) + (b) total content” represents the total content of component (a) and component (b) in the composition for hologram recording media.

The ratio (OH/NCO) of the hydroxyl group of component (b) to the isocyanate group of component (a) was 1.0 in all Examples and Comparative Examples.

In all of the hologram recording media of Examples and Comparative Examples, M/# changed depending on the amount of additive added.

In Comparative Examples 2 to 9, TEMPOL was used as the additive. When HLM101 was used as component (c), M/# was highest when the amount of TEMPOL added was 1 in molar ratio with respect to the photopolymerization initiator of component (d), and the value was 39.0.

When BDTPA was used as component (c), M/# was highest when the amount of TEMPOL added was 0.72 in molar ratio with respect to the photopolymerization initiator of component (d), and the value was 35.0.

In Examples 1 to 4, 3-HO-ABNO as component (e) was used. When the added amount was 2 in molar ratio with respect to the photopolymerization initiator of component (d), M/# was highest, and the value was 41.7.

In Examples 5 to 10, 5-HO-AZADO as component (e) was used. When HLM101 was used as component (c), M/# was highest when the amount of 5-HO-AZADO added was 1.43 in molar ratio with respect to the photopolymerization initiator of component (d), and the value was 48.2.

Even when BDTPA was used as component (c), M/# was highest when the amount of 5-HO-AZADO added was 1.43 in molar ratio with respect to the photopolymerization initiator of component (d), and the value was 44.6.

As described above, in the optical element use of the AR glass light guide plate, a higher M/# can brighten the projected image and widen the viewing angle. M/# = 1.25 times (39.0 → 48.2) is equivalent to 1.5 times the diffraction efficiency and means that the luminance is improved by 1.5 times.

Additionally, in memory applications, recording capacity can be improved by improving M/#.

Therefore, when using the hologram recording medium for these purposes, it can be said that component (e) related to the present invention used in the examples is preferable to TEMPOL in the comparative example.

TEMPOL used in Comparative Examples 2 to 9 is sterically hindered by four methyl groups around the nitroxyl radical group that traps the radical.

On the other hand, since component (e) used in Examples 1 to 10 has no steric hindrance around the nitroxyl radical group, it is thought that the efficiency of trapping radicals is increased and M/# is improved.

This characteristic is thought to be common to compounds with little steric hindrance around the nitroxyl radical group or to compounds with a low redox potential.

[Evaluation of Archival Life (Accelerated Test)]

Three hologram recording media on which the recording of Comparative Example 4, Comparative Example 7, Example 3, Example 7, and Example 10 had been completed were prepared, under dry air at 80°C, for a predetermined time shown in Tables 4 to 8, respectively. Heated. After heating, M/# of the hologram recording portion of the medium was measured. M/# was measured three times each, and the highest value was taken as M/#.

In addition, the diffraction efficiency (irradiation angle -19° to +19°) of each hologram recording medium at the start of the acceleration test and at the end of the acceleration test was measured.

The compositions of the compositions for hologram recording media of Comparative Example 4, Comparative Example 7, Example 3, Example 7, and Example 10 are shown in Table 3, and the measurement results of M/# are shown in Tables 4 to 8.

In addition, the above evaluation results in Comparative Example 4, Comparative Example 7, Example 3, Example 7, and Example 10 are shown in FIGS. 3 to 7, respectively.

In Comparative Example 7, M/# decreased depending on the acceleration time, and M/# decreased by 15 to 20% in 870 hr. As shown in FIG. 3, this corresponds to a decrease in diffraction efficiency by approximately two-thirds. Similarly, in Comparative Example 4, M/# and diffraction efficiency greatly decrease.

Unlike smartphones, AR glasses, one of the wearable devices, are assumed to be worn and used on the body at all times. Therefore, it is believed that there are more opportunities for exposure to hot environments, such as in cars in the summer or in high-temperature areas of plants, compared to conventional electronic devices. Therefore, when using the AR glass light guide plate in an optical device, it is important that the diffraction efficiency does not change over a long period of time even when exposed to a hot environment.

In the additive TEMPOL used in Comparative Examples 4 and 7, M/# decreased significantly in an acceleration test at 80°C, so when used in an optical element of an AR glass light guide plate, the luminance of the projected image decreased significantly. , the viewing angle becomes narrow.

On the other hand, in Examples 3, 7, and 10, the decrease in M/# according to the acceleration time was hardly observed. For example, in Example 7, it was about 2% at 857 hr. Therefore, when AR glass is used in an optical element application as a light guide plate, no decrease in luminance of the projected image, worsening of color unevenness, or narrowing of the viewing angle occurs even when used in a high temperature environment.

Additionally, in memory applications, information is not lost even if the recorded medium is exposed to a high temperature environment for a long period of time.

Therefore, when using the hologram recording medium for these purposes, the additives used in the Examples can be said to be more preferable than the additives in the Comparative Examples.

Since the additive TEMPOL used in Comparative Examples 4 and 7 has four methyl groups around the nitroxyl radical group, the potential energy of the NO-C bond of the dormant species increases due to the steric hindrance of these methyl groups, and thermal cleavage of the bond occurs. The activation energy of becomes small, that is, it is thought that it is easy to cleave.

On the other hand, the additives 5-HO-AZADO and 3-HO-ABNO used in Examples 3, 7, and 10 do not have steric hindrance around the nitroxyl radical group. For this reason, the potential energy of the NO-C bond of the doment species is lowered, and the activation energy for thermal cleavage of the bond increases, that is, it is thought that thermal cleavage is difficult to occur.

This characteristic is thought to be commonly expressed in all compounds with little steric hindrance around the nitroxyl radical group or with low redox potential.

Although the present invention has been described in detail using specific embodiments, it is clear to those skilled in the art that various changes can be made without departing from the intent and scope of the present invention.

This application is based on Japanese Patent Application 2018-150115 filed on August 9, 2018, and is incorporated by reference in its entirety.

S: Hologram recording medium
M1, M2, M3: Mirror
L1: Semiconductor laser light source for recording light
L2: Laser light source for playback light
PD1, PD2, PD3: Photo detector
PBS: Polarizing Beam Splitter
1: LED unit

Claims (19)

Component (e): A composition for a hologram recording medium containing an isocyanate group or a compound having an isocyanate-reactive functional group and a nitroxyl radical group, wherein component (e) contains the following component (e-1). Composition for media.
Component (e-1): A compound having a heterobicyclo ring structure or heterotricyclo ring structure in which the carbon atom of the bicyclo ring structure or tricyclo ring structure is substituted with a nitroxyl radical group. Component (e): A composition for a hologram recording medium containing an isocyanate group or a compound having an isocyanate-reactive functional group and a nitroxyl radical group, wherein component (e) contains the following component (e-2). Composition for media.
Component (e-2): Compound represented by the following formula (I)

In formula (I), C ₁ and C ₂ represent carbon atoms. In formula ( _{I )} , ^{two R When R ​} _​ ^​ _​ ^​ _​
In formula (I), and R ^A in the linking group is hydrogen atom, halogen atom, C1-12 alkyl group, hydroxy group, hydroxy(C1-12 alkyl) group, amino group, amino(C1-12 alkyl) It represents a substituent selected from group, isocyanate group, and isocyanate (C1-12 alkyl) group. In addition, R ^A in formula (I) and in the above linking group is bonded to one or two carbon atoms of the bicyclo ring structure or tricyclo ring structure, respectively, and when the substituent is two or more, The substituents may be the same or different. A plurality of R ^A in formula (I) and the above linking group may be the same or different.
However, at least one of R ^A in formula (I) and the linking group is selected from a hydroxy group, a hydroxy (C1-12 alkyl) group, an amino group, an amino (C1-12 alkyl) group, and an isocyanate group. represents one or more substituents. The method of claim 1 or 2,
A composition for a hologram recording medium, wherein the composition for a hologram recording medium further contains a matrix resin, component (c): a polymerizable monomer, and component (d): a photopolymerization initiator. According to claim 3,
A composition for a hologram recording medium, wherein the matrix resin is obtained by reaction of component (a): a compound having an isocyanate group and component (b): a compound having an isocyanate-reactive functional group. A composition for a hologram recording medium containing the following components (a) to (e), wherein the component (e) contains the following component (e-1).
Component (a): Compound having an isocyanate group
Component (b): Compound having an isocyanate reactive functional group
Component (c): Polymerizable monomer
Component (d): Photopolymerization initiator
Component (e): A compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group.
Component (e-1): A compound having a heterobicyclo ring structure or heterotricyclo ring structure in which the carbon atom of the bicyclo ring structure or tricyclo ring structure is substituted with a nitroxyl radical group. A composition for a hologram recording medium containing the following components (a) to (e), wherein the component (e) contains the following component (e-2).
Component (a): Compound having an isocyanate group
Component (b): Compound having an isocyanate reactive functional group
Component (c): Polymerizable monomer
Component (d): Photopolymerization initiator
Component (e): A compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group.
Component (e-2): Compound represented by the following formula (I)

In formula (I), C ₁ and C ₂ represent carbon atoms. In formula ( _{I )} , ^{two R When R ​} _​ ^​ _​ ^​ _​
In formula (I), and R ^A in the linking group is hydrogen atom, halogen atom, C1-12 alkyl group, hydroxy group, hydroxy(C1-12 alkyl) group, amino group, amino(C1-12 alkyl) It represents a substituent selected from group, isocyanate group, and isocyanate (C1-12 alkyl) group. In addition, R ^A in formula (I) and in the above linking group is bonded to one or two carbon atoms of the bicyclo ring structure or tricyclo ring structure, respectively, and when the substituent is two or more, The substituents may be the same or different. A plurality of R ^A in formula (I) and the above linking group may be the same or different.
However, at least one of R ^A in formula (I) and the linking group is selected from a hydroxy group, a hydroxy (C1-12 alkyl) group, an amino group, an amino (C1-12 alkyl) group, and an isocyanate group. represents one or more substituents. According to claim 2 or 6,
A composition for a hologram recording medium, wherein the compound represented by the formula (I) is a compound represented by any of the following formulas (Ia) to (Ic).

R ^A in formulas (Ia) to (Ic) has the same meaning as in formula (I). A composition for a hologram recording medium containing the following components (a) to (e), wherein the component (e) contains the following component (e-3).
Component (a): Compound having an isocyanate group
Component (b): Compound having an isocyanate reactive functional group
Component (c): Polymerizable monomer
Component (d): Photopolymerization initiator
Component (e): A compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group.
Component (e-3): A compound whose nitroxyl radical group is not subject to steric hindrance, and is selected from (e-3-1) to (e-3-3) below.
(e-3-1): A compound in which the number of alkyl groups covalently bonded to each of the two atoms covalently bonded to the nitrogen atom of the nitroxyl radical group is 0 or 1.
(e-3-2): A compound in which among the two carbon atoms covalently bonded to the nitrogen atom of the nitroxyl radical group, at least one carbon atom is covalently bonded to one or more hydrogen atoms or halogen atoms.
(e-3-3): A compound in which both of the two carbon atoms covalently bonded to the nitrogen atom of the nitroxyl radical group are covalently bonded to one or more hydrogen atoms or halogen atoms. A composition for a hologram recording medium containing the following components (a) to (e), wherein the component (e) contains the following component (e-4).
Component (a): Compound having an isocyanate group
Component (b): Compound having an isocyanate reactive functional group
Component (c): Polymerizable monomer
Component (d): Photopolymerization initiator
Component (e): A compound having an isocyanate group or an isocyanate-reactive functional group and a nitroxyl radical group.
Component (e-4): A compound in which an isocyanate group or an isocyanate reactive group is substituted in the compound parent having a nitroxy radical group, and the redox potential of the compound parent having a nitroxy radical group is 280 mV or less. According to any one of claims 5, 6, 8 and 9,
A composition for a hologram recording medium, wherein the ratio of the total weight of the propylene glycol unit and tetramethylene glycol unit contained in component (b) to the total weight of component (a) and component (b) is 30% or less. According to claim 10,
A composition for a hologram recording medium, wherein the weight ratio of the caprolactone unit contained in component (b) to the total weight of component (a) and component (b) is 20% or more. According to any one of claims 5, 6, 8 and 9,
A composition for a hologram recording medium, further comprising the following component (f).
Component (f): Curing catalyst According to any one of claims 5, 6, 8 and 9,
A composition for a hologram recording medium, wherein the molar ratio (component (e)/component (d)) of component (e) and component (d) in the composition is 0.1 or more and 10 or less. According to any one of claims 5, 6, 8 and 9,
A composition for a hologram recording medium, wherein the content of component (c) in the composition is 0.1% by weight or more and 80% by weight or less, and the content of component (d) is 0.1% by weight or more and 20% by weight or less relative to component (c). According to any one of claims 5, 6, 8 and 9,
The total content of component (a) and component (b) in the composition is 0.1% by weight or more and 99.9% by weight or less, and the ratio of the isocyanate reactive functional group contained in component (b) to the number of isocyanate groups contained in component (a) A composition for a hologram recording medium where the ratio is 0.1 or more and 10.0 or less. A cured product for a hologram recording medium obtained by curing the composition for a hologram recording medium according to any one of claims 1, 2, 5, 6, 8, and 9. A laminate for a hologram recording medium, which has the cured material for a hologram recording medium according to claim 16 as a recording layer, and has a support above and/or below the recording layer. A hologram recording medium obtained by subjecting the cured material for a hologram recording medium according to claim 16 to interference exposure. According to claim 18,
A holographic recording medium that is an AR glass light guide plate.

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